The muffler catches and holds some of the water from the CATs and will deteriorate the metal over time. Condensation builds up with temperature changes. Rocks chipping the coating of the muffler allows for rust.
Mufflers also have a weep hole designed to let the water drip out. This hole will tend to get rusty. The other holes, couldn't say for sure. Unless you have a change in the muffler tone or its allowing exhaust gases to build under the car instead of getting them past the bumper, I wouldn't worry on it.
As for your mod suggestions, get with Ed at Xtreme Racing Tuning on remapping and improving the stock fuel map. If you want more kick, turbo or supercharge it with remapping. Suspension is easy, Whiteline has distributors all over Sydney.
A good combination will make the coastal roads a lot more fun.
Mufflers also have a weep hole designed to let the water drip out. This hole will tend to get rusty. The other holes, couldn't say for sure. Unless you have a change in the muffler tone or its allowing exhaust gases to build under the car instead of getting them past the bumper, I wouldn't worry on it.
As for your mod suggestions, get with Ed at Xtreme Racing Tuning on remapping and improving the stock fuel map. If you want more kick, turbo or supercharge it with remapping. Suspension is easy, Whiteline has distributors all over Sydney.
A good combination will make the coastal roads a lot more fun.