Just say you've bought something else if they chase you up.
I've got a new-found respect for French cars recently. We're doing a project at the moment, based on an R-reg Clio. This car hadn't been serviced for ages, it had been flooded at Glastonbury, run around unserviced and then abandoned in the office car park. We were expecting it to be knackered.
However, I changed the battery, turned the key, and it fired up first time! Put it in reverse, and the brakes came unstuck. Smooth and quiet idle, and all the electrics worked too!
It failed its MOT on brakes (expected after a long time spent standing), a sidelight and brake bulb, empty screenwash bottle and three failed exhaust hangers (the rear beam was the only thing holding the system on!). Other than that, it was fine!
We've changed the cam and auxiliary belts to be on the safe side, and given it a full service, and it's been absolutely on the money since. I reckon it needs a CV joint soon though.
How many of you reckon your Polo would last a year in a car park and be near faultless afterwards? I know mine would get the hump.