ET 24 should be fine. its the same as having a 11mm spacer on
I also currently run 16" 7.5J with 215 40 tyres, but far too much tire for my liking.
personally i'd put 195 40 16 on them.
I also needed a 6mm spacer on the fronts to clear the
coilovers. Rears I fitted 15mm ones iirc, but thats more for looks.
I'm now looking for a 7J front 8J rear set of rims, and be wrapping them in 165-40-16 and 195-40-16
should be quite a bit of stretch
if you want stretch refer to website:
clicky