I’ve been tempted to put 5-series or 6-series or 7-series wheels on some of my E30s, but I can’t.  The former use 5 lug bolts; the E30s use 4.

Also, the E30s tend to use 14-inch rims whereas the larger cars tend to have 15-inch-or-larger rims.

Fortunately, some places sell decent used tires in the 14-inch rim size.