I just recieved a set of SSS (Stainless Steel Systems)Adrenaline Axle backs and REALLY like them. They bolted right up and sound really nice without being overly aggressive.
My pony now definitely has a muscle car sound that really brings the exhaust note to life.
The quality of these pipes are great ( I did a lot of research- LOTS!) and after talking with the owner of SSS, i decided to get them and am really glad I did.
I was really torn about getting the boomtubes (almost ordered them instead -- THAT close) but was concerned about the appearance with the look of the baffles right in the tip - thought it looked cheap - plus I didn't want exhaust that sounded like a teenager looking for attention.
A note on the install - took about 40 mins total...very easy with great hardware and the quality and finish of both the 4" tips (super nice), the mufflers, clamps, and pipes are outstanding. They look awesome as well.
I did end up taking it to my local 'muffler-guy' to get them 'fined tuned' as far as fit in the rear fascia openings...I just would rather spend the $40 and have them bend ( the hangers) and position them to really end up with a timely and nice job.
Great set of axle backs for $300!
Boom Tube Dual Exhaust Kit For 2010 mustang 
(Mods in profile)
