Only one - an Audi A2 1.6FSi
After owning a 1.4TDI for 5 years we figured when Mrs FB needed a bigger car to replace her smart the A2 would fit the bill; in terms of how it drove and performed we loved it but the £400 light drove me to near madness - everytime the engine warning light came on it was nearly £400, the engine was unique to that car so no non OEM parts could be sourced, I reckon in 16 months it cost is about £1,600 in unexpected maintenance. I got shot, the only redeeming factor was that I bought it off a trader who had no idea of the £6k of options fitted so once straight I sold it private and only lost £600 on the price but the cost of repairs means I still took a bath.
I still own the TDI and in 10 years if has cost me less than 1/3 in unplanned repairs than the FSI did in 16 months!
Great engine, when it worked.