:o Nope not true but that only depends on what you want to do!
For Ex: I just installed an Excelon deck in my wifes G20t 2000 the only thing's I put in besides the deck was a wiring harness, an adapter for the antenna & I custom made the adapter kit for the deck to fill in the gaps, as far ass I know no one makes a kit for the G I kept going to all the stereo shops Baddguys Cicuitsucks Best ripoffs & other shops every one looked at me

basicly like that I dunno what would fit I tried the one in my pathfinder & it look cheesy so I made one out of the brackets that are on the bose stereo & some Black plexi glass.
It goes very well with the car & makes the deck look that much prettier in there!:licker:
BTW the tweets & door speakers are handling the extra power quit nicely sounds cleean my wife now want's the BASSSSSS!
Hope that helps my .02