VW Polo 1.4 auto 2000 Engine management light probs

[M'lady]

Can anybody offer me advice? New to this site but relieved to have found it!! Bought a year 2000 Polo 1.4 automatic this week. As soon as I picked it up the ABS light came on. Got home as garage shut. Next morning lght gone off. Car running fine but sounds slightly blowy, especially when 1st started. Later that day the exhaust emissions light came on and stayedon. (Is MOT'd til aug 2008 by the way). Took car back. They 'fixed' it. Later same day the light came on again. Car still running fine! Sat at some traffic lights on way back to garage and the headlights appeared to loose their brightness and car felt like it was trying to stall!!!! Panic Switched of lights and on again, car working perfectly again...maybe this was just coincidence. As I pulled up to garage the ABS light came back on (this was as I bumped GENTLY up the curb to park. Am scared Ive been given a duff car. But am confused as it appears to be working perfectly apart from slight hiccup earlier. Anyone any advice?