I have been searching the forums alot lately and plan getting an xb in june. I have read about wheel spacers and I was wondering if they negatively affect the car or handling. I thought I read a post that said it did but I'm not sure. It it better to get wheels that will fit perfectly or is it okay to put a 15mm spacer in the rear?

15mm why would you need that much. normal is 2-3-5 mm 15mm is deep you will loose alot of bolt threads

spacers are fine as long as you dont buy the cheapo's, stick with H&R. 15mm to 20mm is perfect for the rear since the difference in the front and rear wheels is 1 inch (25.4mm). you don't have to worry about the studs because you have to replace them with longer studs if you put anything bigger than 5mm spacers on the vehicle.