My guess is making a rectangular coolant reservoir is not the issue. It is probably being able to sell it as a 'clean kit' that is the problem. I am guessing you need to extend the harness and potentially use some OEM BMW connectors they do not sell etc.
Then again their intake manifold requires the end user to hack up their OEM harness to extend it so maybe there is something else?
Then again their intake manifold requires the end user to hack up their OEM harness to extend it so maybe there is something else?