Well its one of the few exhaust system manufactures that GUARANTEE that their products provide additional power.
Their quality is in the top range
In terms of BMW aftermarket/tuning companies does following use supersprint:
Hartge, Hamann, Breyton Design, Racing dynamics
or said in another way - if you purchase one of above - will you eventually get supersprint.
And Supersprint fits stock cars.
20 HP additional power - that do I not believe in, but some improved power will you get, that for sure. In fact, if you don't get any additional power, does supersprint offer a world wide money back guarantee.
And hey, pssst, supersprint is avaiable in a store close to you. - Supersprint will be listed after our next major server upgrade.
I'm about ready to buy the supersprint muffler for my '99 528i. PM me a price and I'll probably buy in about 30 days. I don't know if I need the connecting pipe also or not. I think Supersprint offerers 2 mufflers and I am looking for the least expensive dual tip muffler I can get. (This is more for appearance than performance because I have a Racing Dynamics rear apron with exhaust cutout.)