What size spacer should I use on the rear to "flush out " my wheels? Lowered on Eibach sportlines , wheels are 19 x 8 1/2 with 38mm offset, with 235/35-19 tires. I'm hoping to be able to use the Ichiba 15mm version II so I won't have to hassle with the wheel studs. Thanks for your help!

 

Good to go with 15mm. Keep in mind that not messing with the wheel studs using the spacers you referred to is dependent upon the back of the wheels that you have:
http://www.ichibausa.com/15albowhsp10.html

For anybody who wants to know... if you have the same size & offset wheels at all 4 corners, and have the same size tires at all for corners, and don't rub on the front; then 15mm spacers are what you want so that the rear wheels match the flushness of the front wheels. This does not mean that one or the other will be perfectly flush with the fenders, just that they will match. If you're staggered or have different offsets, then all bets are off, and you're on your own.

 

Thanks for the reply CIONIDE ! Yes , I was aware that you have to have "recessed pockets or holes" in the wheel that you're mounting on your car. But good looking out!