Could not solve a P0304 code problem: changed all 4 ignition coils and all four plugs, still failing. The Mini dealer finally determined that the ECU was bad. Replacement cost was $2400, and only $200 of that was labor. Ten year old car with 110k miles, no way I was going to spend that kind of money. Found The ECU Pro through some Mini forums, and sent them the ECU and a key. Turns out this is a known problem with the Mini ECU, and so common that The ECU Pro folks knew almost exactly which components had to be replaced. My ECU was analyzed the day after they received it, they emailed with the diagnosis, I ok'd the repair, and the ECU was on its way back to me the next day. Very satisfied.