My new l322 came with these 22 inch overfinch wheels ( not sure how to determin if they are overfinch tbh?) anyhoo I've read the low profile tyres and 22's affect ride quality and are a nightmare with potholes ect..i stay in Edinburgh and the towns littered with potholes...im planning on sourcing a nice set of 20 inch l405 alloys instead...any pointers in terms of them fitting ,changing nuts ect that I will need to know? Ta

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Later genuine ones had Overfinch on one of the spokes. Earlier ones have it stamped on the rear - but there are probably more copies than originals out there....

There are 2 styles of nut - and they need to be marched to the wheel - the thread on the car remained the same. The difference is the shank diameter - there's a thread here that explains the difference
(If you haven't found it yet, the Wiki contains a lot of useful info )

Other than the correct nuts. the L405 wheels fit straight on - nothing else needed.

Be careful of you use the scissor jack in the boot though - they are notoriously crap - use a trolley or bottle jack

Brilliant! Investing in a trolley jack before I even think about buying new ones..thanks for the help!