@Shakeel
PM to follow, but my quick reply: This is one of those instances where I can say "did this, done that". The wrong size rim and offset will bugger up the drivability of your e90 as well as your odometer reading. A spacer cant fix this problem. It would also be difficult to recommend the right size spacer for your car, you may order a 10mm and find you needed a 15mm...these spacers cannot be ordered for testing.
Its a tough call to make, but the rim may look great on your car and it may not cause adverse drivability at this point but I would replace it for the right size & off-set suited to your car - purely from a long term safety & wear perspective. :idea: