I wouldnt think it would be worth the hassle and money of a blow thru if your just using a generic sub

I dont think you would really need a custom box built. All a "blow thru" is is cutting a hole from the car to the trunk so the bass can "blow thru"

When I used to own a s10 regular cab I was thinking about building a blow thru from the bed to the cab but didnt due to having to cut up the truck.