The only SQ issue you would have is 'motor noise' would be a bit more aparent, seeing as the sub's motor will be inverted and sitting right next to you. But lets face it, if you're trying to squeeze a 'supersub' in your regular cab, you are not building an all-out SQ setup. I doubt the motor noise would bother most people, if they even noticed it.
If I had a regular cab and wasn't going to do a blowthru, Id definitely be inverting a sub between the buckets. Its a relatively common install in reg cabs now a days. Good luck. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif