If your car dosen't look that 'flashy' you won't be pulled over as much. Some things that really catches a cops eye are big shiney loud mufflers, lots of performance stickers, bright neons and over the top body kits (just keep it simple). Most cops don't know much about cars so if it not noticeable to them you will be safer. Things like turbos and ,pods,blow off valves should be kept out of sight as much as possible, nothing like polished turbos and blow of valves or intercoolers. Oh and gauges have as less as you can preferably not on the dashboard or sides.
Things like thins can really keep you out of the inspection bay.