are still using them on their cars. I know how many were sold, and I know the small number of cases where a customer had problems of which I was happy to offer help to correct, and in a few of those cases after exhausing all options, I refunded their money and sent my apologies for the inconvenience. But I never gave up on it - the double-pass radiator setup on my personal ZTT went through the necessary revisions and track testing to validate its performance and it will be available for purchase in short time. I'm sure there will also be cases with that product where people have overheating problems - these vehicles seem to have inherent overheating issues and people with OEM cooling setups on unmodified cars come across overheating problems for one reason or another. And in cases where this occurs, I will take care of my customer to their satisfaction.