Luan Pra bang

Ever since I gave my sister my car to look after while I was away it has had an urge to drive itself almost like it was wearing 200/18inch tyres as opposed to the sixteens that it actually has. It drove perfectly before and now feel's the need to aim itself at kerbs and the like. I have had the tracking checked but don't really trust the garage that did it but I think it might be shock absorbers is this likely ? any other ideas ? and does anyone know a good place in teh south to look at these things ?

TIA