unstable at speed

[weezer]

Okay nobody has asked this yet. I recall you mentioned that everything is stock; including rims and tires? How wide are the tyres and when you bought new ones 5/6 months ago, is it a different brand than the previous ones you're used to? It could very well be tram-lining. This happens when wide tires are applied and certain brands are more susceptible to it. Tram-lining refers to when tires follow every single groove on the road surface just like a tram on a track.
Good luck with it.

[nigeltee]

rims and tyres are stock. tyres are pirelli p6000 in 205 60 15. the rims are bmw alloys 10 spokes i think. i didnt really drive the car very much before getting these tyres, cos they were changed within a week of me buying it. the originals were all cracked and looked dodgy.

Thanks for your thoughts.