I recently decided it was time to start looking for a replacement for my e86 after 4 years and 46k miles. Just test drove an e92 and actually liked it a lot more than I thought I would. If the trade in offer had been a little higher, I may have made the deal on the spot. Still, like the OP, can't get over the thought of giving up the unique look of the Z4MC. I was hoping the answer would be in this thread, its not, but I appreciate the OP and the rest of you posting your thoughts on the issue, it helps. Sort of.....
