I also bought a Z3 this year. Mine was not a gamble I bought it from an elderly co-worker. I have been telling him for years to let me know when he's ready to sell. I almost passed on the car because the air bag light was on. Bought it anyway and it was one of the best moves. The fun to cost ratio is over the top, a true sports car!!
6K miles later air bag light is still on probably the seat belt recepticale but I,ve been spending my cash on fuel I'll have it repaired when I comes out of winter storage in april.