just to let peeps kno that you can do this. a couple of months ago i booked a 24h test drive in a 172 (cos i wondered what is was like), ended up having it nearly 48h! possible cos renault do a 24h test drive so bullsh*t to them and they give you the car as they want business. im also with co-op insurance who do not charge for this so all i paid for was £5 petrol.
go forth and test drive!