If you have the extra money I'd get the Type X Pros... they are about twice as much though, and you can get a lot of different components for $350... I'd try and get some kickpanels or modify your door panel to get a 6.5" mid in there somehow, although having owned a Grand Prix and a Regal, I know GM is infamously gay for not leaving a ton of room to play with. Kickpanels are always a good option though... the 5.25s just don't seem to do very well on the midbass... especially if you are going with bigger subs, you may notice a 'hole' in the sound between 60-100Hz unless you really tweak it.