is to hire a car yourself for a day and see what happens. You will also get the idea of terms needed in the rental agreement.
Insurance is something you need to look at carefully as most specifically prohibits hiring out.
Initial risk is will they bring the car back? and what will you do if they don't? A tracker would be a worthwile addition.
You definitely need a good lawyer to draw up the rental agreement officially to make it watertight and binding and not breaching any copyrights from the hire company you test rent from.
You need to know what to do about damages, levels of petrol/diesel etc at start and end of each rental. People are generally less careful with hire cars than their own and you need absolutely clear policies in place so everyone knows where they stand legally.
I expect you will also need a tame mechanic to look after the vehicle and keep it legal at all times.
Hope this helps a little.
Best of luck
