1) If your stereo is anything but stock, buy and alarm. 2) Don't park a nice modified car on the street. 3) Don't leave your wallet in your car. 4) Don't place amplifiers and speakers in conspicuous locations where they can be seen. 5) Get on local import boards and post up a WTB for an SAFC and boost gauge.
"The 300ZX Turbo is a dance; it's a song; it's rolling, roaring automotive art. There is no color that doesn't suit it. There is no mood-lifting chemical substance it can't replace." - Automobile Magazine