ask for a test drive first and while you are at it find a car park that is empty and do a slow reverse to test the vcu if it feels like braking then the vcu is shot also look for any oil drips front and back and ask what warranty is on it , also how many miles has it done and what services has it had, if it is auto has it had the gearbox fluid change at 60,000 miles check tyres are all the same make and have tread on them as if it has different tyres this can ruin the VCU the back diff and the ird. you have been warned but if these are all good then take the plunge and you will find plenty of help on here if you get into trouble once you have introduced yourself