As others have mentioned, I have arrived several times to hear the we don't have your car but for $XX a day, you can have this one. I usually just have to tell them No about six times and then they give me the bigger car.

I've never had to pay for an upgrade under circumstances like that, though there might be third-tier companies out there trying to do what you mention. I've had a time or two where the whole lot was empty and they were dispatching cars as fast as they could clean them. In those circumstances if you had a high-level car reserved you'd be stuck for a wait. But thankfully I've never had that happen with Hertz, Avis or National, and even Alamo seems to be getting better.

I've also had a case or two where I've gotten upgraded from a compact all the way to a minivan or SUV for lack of other cars on the lot. I learned for the first time what gas-guzzlers the SUVs were in such a case on a 2-week rental 5 years ago; with prices as they are today I'd have to turn it down.

Am also noticing less pricing spread between compact and full-size on weekend rentals (am a big leisure traveler). On some of my bookings of a mid-size, the full-size (2 notches higher) was only $2/day more. That might indicate they're having more trouble than in the past in renting out the bigger cars, possibly because customers are more conscious of fuel economy.

The only semi-unpleasant "your car is not available" experience I've had was with Alamo, and they didn't have our family's minivan (reserved on a dirt-cheap leisure rate). We eventually persuaded them to give us two midsize cars instead for no additional charge, however, which worked out fine.

I also keep getting automatics from Hertz in TLV when I reserve sticks. I think they don't trust Americans with sticks.

I had this happen once with Dollar at BDL. I reserved a mid-size, and when I got to their location I was told all they had in the mid-size category was a Jeep Wrangler. In my mind a Jeep Wrangler is not the same as a 4 door vehicle with a trunk and suspension, but they wouldn't budge. My only option was a $9/day upgrade to an Altima (which Hertz considers a mid-size). I took it, wrote to Dollar when I got home, and a few months later finally got my money back. I didn't get an apology letter, and I will never rent from Dollar again.

I've had this happen with more than one company where they will try to upsell you and, when you decline, magically you wind up with the proposed vehicle anyway because the class you wanted is sold out.

Having said that, I do NOT buy into this "upgrade" label. I rent what I need for the specific trip. There are reasons why I may not want a larger and/or less fuel-efficient vehicle. I do photography in national parks and wildlife refuge. Often the roads are narrow and parking space is limited. A larger vehicle can be a problem. Plus, sometimes the distance between gas pumps is significant. And then there's such things as $30K in camera gear in the back of an SUV with no trunk or cargo cover so that it's visible to potential thieves.

And, having said that, where does Hertz get off calling a Cavalier an intermediate car when the rest of the industry and the free world knows it's a compact???

I was given a nice convertible once without paying any extra for it. I don't know if they were out of normal cars or not.

If it happens again I might try to negotiate something else. It was December in the midwest.

I always use Thrifty, and they don't impress me as the sort that would play games at their customers' expense.

It may be interesting to see whther the late charges increase with a car upgrade - if you are an hour or two late - would you pay the upgraded cars' hourly fee, or the hourly fee for the car your originally booked?

I have had several situations in which I was "upgraded" without charge to a car in a higher class. I have had so many bad experiences with GM rentals I try to avoid them as much as possible (fewest bad experiences have been with Pontiacs and Buicks, so if only GMs are available, I go for those). I have "downgraded" my rental on several occasions to get better quality cars in lower classes, such as Camry's or Corolla's. I never asked for or was offered a reduced rate when I do this, since the few dollars I might have saved in these situations were not worth the add'l time.

By the way, I have on several times been stuck with a vehicle I did not want (too large, not enough trunk space, etc.) because the airport location was out of other sizes. With at least most of the majors, you can go (and I have gone) to another of their rental locations and do a vehicle exchange. The neighborhood location might be glad to get that barge while you take one of their 10 mid-sizes. I've only run into one situation in which the location was not allowed to do this because of some franchise requirement, although I felt like the manager would have if he could.

While it's too late for your deadline, I'll add my experiences here in case anyone might profit from it. I always book rental cars at the absolute rock bottom rate in the smallest sub-sub-sub Playskool sized car available. I've been known to use priceline for this purpose. On each of the last four times I've picked up my car, I've been asked if I want to upgrade to a [fill in the blank] for [fill in the dollar amount] each day. Each time I've declined, and each time I end up getting the upgraded car anyway. I've always attributed this to agent not having the sub-sub-sub compact car available, so they're trying to talk me in to paying for the upgrade that they're going to give me anyway if I decline to pay, but by trying, they at least have a shot of getting some revenue. This has happened to be with Avis, Enterprise, and National.

I usually rent where the price is decent. Lately, I have been doing weekend rentals from Hertz thanks to the nice codes posted on FT. I have been quite satisfied with the #1 Gold service from Hertz.

A few short stories from the 1990's.

1. I arrived at the Alamo at CMH and they asked me if I wanted to upgade from my compact car to a Lexus for $6/day more. I asked if I could use my coupon for $5/day off on a mid size/+. I jumped at the chance to pay only $2 more for the 2 day weekend rental to rent the Lexus. That was in 1996 & they were out of the LS400 so I rented a GS300 instead. Nice car.

2. In the early 1990's, I would reserve a compact car for $62 for a week & I would get a larger car instead. Once, the compact car A/C broke in 110 degree heat & Alamo gave me a new 1992 Caprice that had COLD A/C! I kept the car for 4 weeks paying only $62/week. I drove "old" clunkers at the time & the Caprice was a real treat. Work paid mileage for a couple of out of area trips so the rental was essentially free.

3. Once at FAT, I reserved a smaller car & with my upgrades/coupons, etc., I ended up with a Cadillac deVille & paid only $23 for a 2 day rental. Drove to Tahoe that weekend. ^

4. Reserved a Geo Metro at $39/week in 1987. Was offered a Buick Regal for $20 more for the week. Jumped at the chance as there was 2 of us. Drove all over California that week!

Renting cars for leisure enabled me to keep driving old cars until recent years. Saved alot of $$. I now own my 2nd new car I just bought recently. Will rent cars on weekends for long trips to save putting miles on my car.

I've had it happen several times. I rent small cars because I like small cars. In my experience, Thrifty and Budget usually ask for $$, but if you refuse, they relent. They typically want to downgrade me to an SUV (which I refuse to drive on principle) or PT Cruiser (the ugliest car in history) even when they have the car I want just because nobody else wants those either. I tell them to give me what I want or give me a free car, and though I've never gotten the free car, I did get a free tank of gas for accepting the downgrade from an economy car to a full-size car.

I long for a class-action lawsuit against the rental car companies to stop this fraudulent behavior, but I know there's no way they'll ever be punished. So I've gotten in the habit of reserving from multiple companies - if one won't give me the car I reserved, I can go to another. I've even reserved multiple cars with a single company (one in my name, one in my wife's) to see if that works, but it seems to have little effect.

You've hit a goldmine and its name is Dollar rent a car at Newark airport. The counter help is trained to pad there pay check by telling you your car class, economy, is not available and will not be for 15-20 minutes. They will tell you if you want a car now, you'll have to pay more. Another trick is if you are a few minutes late from your reservation time to rent the car, they will tell you, you have to pay up for a more expensive car because your reservation is invalid. If you show that you will not be intimidated and demand you car now at the reservation price you will get your way. You want a made for TV moment. Send someone with a hidden camera to Dollar at Newark airport at 6:30ish PM on a Friday and arrive a few minutes late for your pickup. They'll try to pull this scam on you. Have not rented from them in over a year because of this.

Ditto

At least twice I was given a larger car at no extra charge because they were out of the one I reserved. In fact, the last time I was traveling with a firend who had reserved a compact. They offered him a mid-size for "only X dollars more" but he declined. Whe we went to pick up the car, there was a midsize waiting at no extra charge.

That's a horrible story! It appears most of us are savvy enough to go to the big companies, where they don't normally try and pull any tricks.

A rental company normally won't force a customer to upgrade, what they will do is offer the upgrade. If you decline, you may get the upgrade for free if they don't have the car grouped you have booked available. No rental car company has ever forced to me to pay for an upgrade over my last 200 reservations.

As for arriving early. Hertz has never tried to pull any tricks with me. I have also arrived days late to pick up a car, even when my reservation has been cancelled, but they reinstated it without any problem.

I choose Hertz because I think it has proved to be one of the best. I have used Avis a lot in the past, but they seemed to be more problematic. They have built a reputation (in my family) for billing for damage that was not apparent when the car was returned.

I think the car companies billing customers for disputed damage is a far bigger problem than forced upgrades, since the excess is often $750 per rental.