Hi Mike
Not so much in the UK (although I remember Richard Hinton running one in Prodsaloons, I was always surprised no-one tried the 323/325 for the BTCC- though you can say the same about the Merc 190, another 2500cc class car successful in Europe, but virtually unknown here other than in prodsaloons), but plenty in Europe, where they were a very popular choice, first in 323i form, then the 325i in 1986.
In particular, the Linder team with Winni Vogt and Christian Danner amongst others, having plenty of success in both DTM and ETCC
http://www.irmler-motorsport.de/irml...older_85_1.jpg
http://www.racingsportscars.com/driv...ni-Vogt-D.html
http://www.racingsportscars.com/type...25i.html?cat=4
Frank Gardner's JPS team used them on occasion in Australia as well. Won't swear to this, but I think we might have a 325i thread somewhere?