There's a couple of guys in Sydney who've been given EPA notices for noise with unresonated exhausts, and the fine is $500 on the spot so you'd best be careful if it exceeds the threshold (see
http://www.epa.nsw.gov.au/noise/motorvehiclenoise.htm for details)
Curious about what you've noted about LED headlights for $20 - you're getting a GTS so you have the LED DRLs already?