Very impressive results, congratulations. I know you have no business interest in doing this, but perhaps a few of your potential customers would like to test your catless downpipes with the rest of the exhaust stock. Is this possible and do you think your stage one tune would work with the stock center pipes and rear mufflers? I'd be curious to see if removing the cats and adding a mild tune would bring more benefit than replacing the system from the cats back and no tune. Also interesting to judge the sound quality of the stock mufflers with the added flow from deleting the cats. Might be a whole new sounding beast!
Secondly, from your experience with BMW, do you think the engine warranty is pretty much gone with the deletion of the cats? And I suppose the same can be said with any tuning of the engine ECU? When any ECU tuning has proved itself reliable over time, I suppose many will not worry and proceed, but at first it is a concern for me at least.