you need a standard car really so that there is no advantage to someone woh's used to driving big power rwd or 4wd types

and no auto's either

if it's got to be fwd then fair enough as i can't see many hire cars being anythng other than that

and most modern machinery is fwd only

or just get a car that no one has currently got, like some sort of basic spec drum braked mk1 with a 900 cc engine or the like