Let me shed some honest salesman knowledge
Yes you can pcp used cars depending on age and mileage as they struggle to put a guaranteed minimum future value on a used car.
You can settle the agreement at any time just like hp, your car us worth x and the settlement is x
Rates on used car pcp can be crap depending on where you are getting it from, bigger the franchise the better deal on the finance. Inchcape hard to beat and at 3.99% flat rate available by us it's not that bad at all.
Evo1986