I know that I have been negative on the Dinan Flash, it is simply a matter of price. But what Dinan does better than any other company is stand behind their products. I have had a warranty claim with Dinan and they are stand up.
it works like this. You need to get your car serviced at a Dinan dealer, preferably a BMW dealer too. Once they find the issue, your Dinan dealer will call Dinan to discuss the issue and then get authorization to do the repair.
The Dinan dealer charges back Dinan for any work. In many ways, Dinan behaves like a car manufacturer for warranty claims.
"Aerodynamics are for people who cannot build engines"......Enzo Ferrari