[v3.0si]

OP - keep in mind the concavity on the rear of your z4 will be much less than what is pictured on that blue z4///m roady. do not expect yours to be that deep if you order wheels based on any rear wheel on an ///m you see. ///m's are significantly different in terms of what will and won't fit.

also, Roffle has it right. stay as close as possible to stock circumference on new tires as you can. the last thing you want is an incorrect speedo, ABS issues, DTC issues, etc...

i do not know of any case that an alignment would be covered under maintenence. you will need to pay for it.