fit in the trunk of the max? would there be enuff room to push the air?

and do you guys think it would be overkill to have 3?

 

It should fit....depending on the way you mount them. For my tastes, 3 12" L7's are definitely overkill....if you get a pair and put them in a ported enclosure, feeding each around 800 wrms, that will absolutely slam.