I contacted ECU PRO after the ecu in my Mercedes suddenly died. They were patient and responsive to deal with, both through emails and phone calls, as we decided how to proceed with my unrepairable ecu. Once I got the required parts shipped in, they promptly made and delivered a clone. The clone failed shortly. While that may sound discouraging, I assure you this was a positive experience. In a car with no blank replacement available, they must source one through a wrecking yard. They have no way of knowing what the donor car went through, so a certain failure rate is to be expected. What impressed me was the response… they analyzed the failure, and determined it was different enough from my original to rule out a problem with my car. Many companies would’ve taken that opportunity to pass the buck. They moved me to the front of the cue and had another replacement clone here within days under warranty. They stand behind their product, and in these days that is a rarity.