Not sure what you test drove, but I almost crapped my self the first time I punched it (while moving). Coming from a Solstice, you should have felt like you were going to smash into the seat. The car I drove prior to the SRT was a 2005 G35 Coupe 6MT with the 298hp engine. The SRT made that car seem like a, well, Scion XB.

Try dropping down one gear by tapping the gear selector to the left, then punch it. You'll probably crap yourself if the car is right.

As for the interior quality, it is very nice COMPARED to many sports cars including pre-2006 Porsches. Yes, the center console is plasticky and the matt finish on the plastics comes off easily, but compared to my Infiniti, it isn't much worse. The door grabs, pedals, and steering wheel accents are real aluminum at least. Don't forget, the Alcantara seats are rare on sub 60k dollar cars. Any nicer, the SRT would have cost 60 grand or more. Gotta cut costs somewhere, they certainly didn't on the drive train.

Oh, also, you have some learning to do. These cars use 99.9% Mercedes and Mclaren-made parts. The engines are hand built by one technician at the AMG factory. As for the quietness question, YES, the car is quiet from the driver's point of view. It is supposed to be a sophisticated sports car. From the outside of the car, it does sound powerful. If it were a muscle car or if I was 20 again, maybe I'd want the car to sound like a motor boat with a 4" coffee can exhaust outlet. If this were a V8 or a V12, I'd change the exhaust, but for a V6, I'll keep it the way it is.