I'm one of many that completed Single Player and have that to use to test cars and I don't understand people that just jump in Online, without bothering to even play Single Player. Yes, they paid for the game and can do what they want and I respect that. I just don't understand people who would skip on playing a (basically) different game. Content Creator is also a good way (which I never use due to first reason mentioned) that everyone can do. But I agree with the topic; we should be able to call Lester and, say, call "Locate A Car" and a drop-down menu shows car classes, pick one, pick a car, voila! You have the car for 24 hours in-game. Cannot be modded or saved. Once destroyed, you need to wait 12 hours in-game to call again. A fee of $400-$800 to use, depending on car class.
That's the best poll I've ever seen.
I love that commercial in GTA IV.
"Who cares, you're on a scooter and they're not."
Also, in-game hour is around...90 seconds? Something like that. Not enough to try it out.