The HFS3 is good for the R53.
The water pump is not hermetically sealed, so you are risking the life of the pump if you put it in the engine bay. We don't warrant it.
I really cannot take this Frankenstein kit project up, it is extremely time consuming, sorry.
Here is a diesel that worked well with aquamist:
http://www.e90post.com/forums/showth...quamist&page=3