Cheap or mismatched tyres are the main ingredient of tracking (or tramlining). Good quality tyres are mandatory on Porsches.
1)Make sure the tyres are up to spec and at the correct pressure.
2) Have a front & rear wheel alignment at a competent Porsche savvy Indi.
3) Get your new suspension arm fitted to match the other new one.
Bush Tyres are located in Boston, Sleaford & Spalding & supply high quality Porsche/Ferrari tyres Tel 0845 680153 or
Tyres, Exhausts, Brakes, Batteries, Alloys & More throughout Lincolnshire - Bush Tyres.
How's windy Boston - I used to live and work in Cleethorpes many years ago......