[mseebach]

The biggest problem with car rental is the paper work - for some reason it can take five-ten minutes per customer to deal with, if nothing goes wrong. I've waited 20+ minutes on multiple occasions. There is literally no reason it can't be handled online well in advance (and it typically is, but for some reason it's repeated in person). Car rental needs something like airline self-service check-in kiosks more than FlightCar, IMO.

[aneth4]

This can be a problem, though I doubt an alternative airport parking based service would be much quicker.

As mentioned by others, Hertz Gold etc really ups the service, but it's usually not worth the 2-4x you pay on the rental.

I've found Payless and Fox both to be the cheapest and provide adequate service. I've had run-ins about fees and such, but generally I fell I get excellent value.

[smackfu]

Join Hertz Gold and there is no paperwork. Totally worth it to me.

[rprasad]

Join any "Gold" or "Executive" level offering from any car rental company. They've offered these plans for years--paperwork is handled when you join, and thereafter your wait time for a car is usually the amount of time it takes you to pull your member card out of your wallet.