Cheers fellas.
The lighting was low (evening sun). I use AG SRP then Collinite wax - look ultra deep gloss in the right light. The only issue that really bugs me is the swirls on black paint - I have bought some Menzerna polishes and a DA to sort them out over the summer.
I lowered my previous E46 M3 cab on Eibachs when the original springs snapped but it was loo low to get on my driveway (it has a lip as it leaves the pavement) and the car bottomed out under the front seats.
I agreed Z4Ms look better a bit lower but I like it as it is - the CSLs do make a massive difference.