What a brilliant build..im stunned!
Ill be keeping a very close eye on this
BTW: two things
1.
Engine oil is great for getting off sound deadening. i know because the cap came off the top of a bottle in my boot and it turned the wheel well sound deadener into a goohy mush, but with a bit a degreaser it cleaned up nicely.
2.
The lip you picked up is off the e30 318is, have a look at the link below, the car in the background has the lip on it.
http://www.m42club.com/images/club_m42_home_03.jpg
Good luck with your project
Paul