I've hauled 8-10' trees, large sound mixing boards, construction lumber and a bunch (4) skinny girls, but never a double bass. (nor any dead hookers).
As long as you can accept that the top needs to come off, you have unlimited space for anything not too wide. As long as the heater is working, it can be livable (with a hat on)
Both trunks are relatively nicely sealed so the smell shouldn't be too bad from the dead body, but remember that rigormortis sets within 24hrs, so having them folded in the front trunk MAY not be the best move.