Rims and tires

hello this is my first post ever on a forum and i just cant seem to find the answer anywhere, I want to put the biggest wheels and fattest tires possible on a stock 1995 325is w/o any modification.

When i first had the car it had 17inc rial rims on it the size for those were 8 JX 17 EH 24 ET 30
the tires that fit it where 225 45 R17 they rubbed slightly so i took them off.

I would love to use those rims again and my other question would be can i keep those rims and put a slimmer tire on or put slim ones in the front and keep them wide in the rear.

First question:
Where was the rub?

Now, if it was on the inside, no worries. Get yourself a pair of 5mm hub-centric spacers and 30mm wheel bolts.

If not, just go to http://www.miata.net/garage/tirecalc.html and check which tires have the closest outer diameter.