Originally Posted by phred
you will probably have to pay a pretty hefty drop fee, AND you'll have to hassle with getting to and from the rental site twice.
I would mess around with the LAX site, looking at the various long-haul transpo options like vans and busses. You may not be the first person who needs to get from LAX to ONT, so there may be options. Alternatively, you could try and cut a flat-rate deal with a taxi company, or take a chance and do it directly with the cabbie himself. I had a chatty cabby once who was regaling me with tales of people hiring him for all-day trips around town of questionable legality, etc.
AMTRAK maybe?
AMTRAK???? There is no train system anywhere near LAX.
There will be no drop fee from Avis. It is actually pretty easy. Go out of LAX and catch the Avis bus to the Avis lot to get your car. If you are preferred (you can sign up on the website), they will drop you off at your car and you go--no contract to sign.
At ONT you drop it off and you take the bus again. It has been a few years since I went to ONT and I only went to the new airport once but I remember it being a very short bus ride and I believe the rental lot is just past the terminals.
It depends on the time of day. Perhaps if you told us that we can give you the best suggestion...