I pretty much agree with everything that's been said - don't be an idiot and you shouldn't have too much trouble. Yes, you're gonna get more attention than if you drove a little Corolla - but if you keep the mods discreet (i.e. no massive loud exhaust, neons, other 'bling', etc) and you're not on P's, you shouldn't be too unlucky.
When I was on P's, in my practically stock N/A 33, I would get pulled up all the time ("RBT" of course... pfft!) - never actually even accused of doing anything wrong (i.e. speeding or skids or whatever) but mainly the cops just wanting to check the power/weight issue (i.e. looking under the bonnet for a turbo) and try to defect the car on principle - just to get it off the road I guess (got 2 canaries in about 2 years... once my rear tyres were a little on the baldish side - fair enough, the other time because my aftermarket steering wheel "didn't have enough padding").
Since I got off my P's, I've only been pulled up twice - once because my rego had expired the day before (my bad, just happened to get a certain well-known import-hating copper from the Knox area, so no warning for me! ) and another time because I overtook an undercover cop (again, my bad!). I've got a FMIC, zorst, etc but I don't drive like a moron and I've not had any real trouble with the boys in blue. Doesn't mean I don't get nervous if I'm ever being followed by one though!