You must be getting a LOT then. The trunk in the Impala is monstrous, with a volume of 18.6 cubic feet. I fit 3 oversized (yes oversized and overweight...) bags into the trunk of one (the long way) along with a box and some other stuff we purchased and there was still some room. Here's a picture (courtesy of one of drzoidberg's ride reports). If an Impala isn't large enough then you want a Crown Vic/Town Car or an SUV/minivan.

-J.