Originally Posted by juld0zer

You have two choices:
1. Delete the factory water/oil heat exchanger sandwich plate and just join the coolant lines together - but you must fit a thermostatic sandwich plate otherwise your oil takes ages to heat up.
2. Stack/piggyback the external oil cooler on top of the stock heat exchanger by fitting the external cooler system's sandwich plate literally in between the stock unit and the standard size oil filter. It's a tight squeeze from people's reports but it's not impossible. I believe Stillen kits require a specific model oil filter which they outline in the instructions.

How to install z1 sandwich plate on 2012