My S4 exhaust MPEG clips:
The stock & Neuspeed Generation 1/Borla were taken from the exact same location/distance.
The VM2 & VM3 were taken as close to that same position so that a somewhat relative comparison could be made between all 4 exhausts.
Exhaust install pics are here: Neuspeed/Borla / UUC VM2 / UUC VM3

Idle/Revving (348 kb)

Neuspeed Generation 1/Borla

Idle (343 kb)
Rev to redline (343 kb)
Revving to multiple RPMs (343 kb)

Idle (343 kb)
Revving to multiple RPMs (344 kb)

Acceleration from stop - VM3 + piggie pipes (192 kb)
Drive by - VM3 + piggie pipes (176 kb)

Thanks to Mr. Piggie for the following 2 clips:
With "Piggie pipes" clip 1 (1.31 MB)
With "Piggie pipes" clip 2 (1.29 MB)

APR v.1 exhaust:
(courtesty of Hugo M)
reving engine (922 kb)
passing through a tunnel (890 kb)

MTM, UUC VM1, & UUC VM2 mp3 sound clips:
(from the former
MTM exhaust (316k)
UUC VM1 (336k)
UUC VM2 (432k)

Other S4 exhaust links
Flyboy's Supersprint exhaust clips
DonP's Forge/Milltek before and after multimedia clips, plus review
Taner's UUC VM2 exhaust clips
Greedspeed's Neuspeed Generation 2 exhaust clip

Contact funkadelic