if he's got the right design wheels (spirally suction-fan-like), then thats a reasonable spot to have the pod, except it will start sucking hot air in the moment the brakes start warming up.

if the turbo is catback and muffler back, i can see it producing less power due to slower exhaust flow, and maybe making it even more laggy. i can imagine it would be nasty if unburnt fuel decided to combust and backfire right into the turbo.