Thanks all. Popped into the garage this evening to "battle" the radio and dash for the aux cable.....was somewhat disappointed that tinker time was just 15 minutes..... had to fiddle a little and remove the little pins from the connector block on the cable I'd been sent as I have sat nav, cd changer etc, but it was pretty obvious by a little trial and error which connector blocks stopped either sat nav or cd audio working when you removed them, so just refitted the pins into appropriate holes in the connector blocks and voila.... aux appeared as an option, and the iPod now works along with everything else . Chose not to fit a fancy type system as I'm quite happy to just use the iPod playlist....
Fitted 2 of the 224 wheels just so I could compare offsets etc. The rears sit somewhat wider than the old ones, but just about flush with the arch so all is well.
The wheels came with what I guess is m size tyres as the rears are 255/40.... not sure if I need to swap them or not yet..... but I might refresh the wheels so can do that with the z4 size tyres 255/35 I have currently.
Happy days !!