I learnt a bitter lesson this week having just bought an ex lease Renault Kangoo, a couple of weeks ago.
I checked the cam belt and it looked almost new. Thinking that as an ex lease vehicle, it had been serviced correctly, I didn't bother to change the belt. What I didn't know was that the belt had been changed, but not the tensioners or idlers. That is why I came home on the back of a recovery truck and why I'm just about to pay out for a head rebuild and a set of idlers, plus various other parts destroyed when an idler collapsed at 40 MPH.
Talking to people after the event revealed that leasing companies often play 'the numbers game'. If they have a number of vehicles they find it more economical to have the occasional failure than to change everything they should do on all vehicles.
Moral of the story is to assume that things haven't been done properly and check them out for yourself. I paid £1800 plus VAT for the vehicle, plus a trip to Newbury from Scotland and now; plus £800 for the repairs, negating any savings I might have made.