Same here. The thing is I have a Capital One Venture X and the rates through the CapitalOne Travel portal are only slightly higher than Autoslash for prepaid rates. I'd rather take the 10X CapitalOne points vs the 2x points I'd get with renting directly and pay a bit more. You get what you pay for, Hertz is more expensive but I have President's Circle through CapitalOne, and so if I book a mid size or above (and for C1 Travel the allow you to enter frequent rental numbers for DollarThrifty Group members including Hertz) I get President's Circle. If I book Dollar or Thrifty I get what I rented and sometimes a free upgrade but with no loyalty points. At DCA where I rent the most, Dollar/Thrifty/Hertz are essentially one. Pickup and dropoff at same location, counters co located and employees the same. The secret to picking a car with Thrifty is to signup for BlueChip. Then about a week before your rental, they will text and e-mail you to check in online. Then about 45 minutes before our scheduled start time, they will text/email another link to pick your vehicle. On my last two rentals, I got what I rented on one (rented standard, got Nissan Sentra) and on the other I got a "free" upgrade to a Chevy Malibu with 53K miles that was filthy. But hey, I was able to use up by CapitalOne VentureX $300 travel credit on both, so no complaints.

Also, I have noticed that prepaid auto rentals can be cancelled within 24 or 48 hours of scheduled start depending on the vendor. It's not like prepaid hotel reservations which are often non refundable 24 hours after you make them. So I have no issues with booking prepaid, just book and put a calendar reminder to cancel if I don't need it.