why when you rent a car they just give you the key and off you go? I mean you might be playing with the electronics and set the speed limiter at 55 or something.
Think about it for a moment.
When you rent a car, you are renting it from a company:
1. with a large fleet
2. with pretty good profit margins
3. with the ability to replace the rental quickly
4. where costs of damage and insurance is spread out among thousands if not millions of customers
5. where, even if you rent from a cheap "mom & pop" operation, there's an awful lot of damage than can be done before it becomes unroadworthy.
Contrast that with the typical FBO:
1. with small fleet, much of which isn't even owned by the FBO but is on leseback from individual owners
2. with extremely small profit margins (or none at all; many leaseback owners are happy just to defray some of their ownership costs)
3. no ability to replace the aircraft quickly, suffering an immediate loss of use and revenue to the FBO, the owner of the aircraft, and the CFIs who teach at the FBO
4. where the costs of insurance are extremely high and, since it's a small market with few companies, not regulated the same way as motor vehicle insurance, an accident results in even higher premiums, sometimes prohibitively so.
5. where the slightest ding makes the craft unusable until inspected and repaired.