I have a '95 NAS D90. Maybe my setup will work similarly for you? If not, you can put in spacers pretty easily between the speakers and door panels.
I put these Polk Audio Marine Grade 6.5" speakers in the front door panels and back left and right corners with a Polk Audio amp (under the passenger seat). They sound pretty awesome, sans major bass, and match the interior nicely with their minimalist design. And they're only $99/pair.
The one thing I didn't do was Dynamat the front door panels, which definitely is on my short list of things to do. There's a little too much resonance when you bring up any degree of bass, but I think they will sound awesome once the Dynamat is in, and the speakers get awesome reviews on Best Buy. Hope this helps.