its not difficult to switch out your tips for larger ones... just look at magnaflow tips ... they make decent quality stuff that wont break your bank... and they're very easy to install, just bring your car to any muffler shop and they should be able to do it for you.
Current: 2013 F10 M5 & 2013 GLK350
997.1 GT3RS (gone)
2009 WRX STI (gone)
e92 M3 (gone)