not sure what product your asking about, Dinan in general? If so Dinan makes a great product, I have Dinan on my roadster, suspension, short shifter, ECU program, and stress bar, I like all of them. Dinan is a bit over priced for the most part, but if you shop wisely you can save. I got my suspension for 40% off by buying it during the winter months.
There are other makers who make the same products for less in some cases, however Dinan has an excellent warranty package which is honored by BMW.
