Scottish Elises

I have just changed the rear tyres for a new set. Keeping the same type Toyo Proxes. Since doing this there is a strange wobble or wondering of the front end. There is plenty tread on the front tyres and pressures are ok. If anyone has any ideas please let me know, thanks.

hay there. Just discovered this site,recently bought myself a s2 111s . Red on a 03 plate. I'm living in dunfermline so if anyone sees it say hi!