06 Beetle loud noise in drive

06vwbeetle

I have an 06 Beetle 5 cylinder, and just the other day, after getting a new battery and they installed it, when I'm driving and step on the gas into overdrive, it gets really loud, almost like a knocking or loud muffler that has a hole it it. However, it doesn't do this when I'm in park and step on the gas. Only in drive. It still has great power, but is loud now. I'm worried that the shop did something to mess it up, but they won't check it. Any ideas what it could be? There is enough oil in the engine.

Mr_Shiftright

Well you'd better get in on a lift and have it checked. I don't see a connection to a simple battery installation but who knows if there was some lift damage, etc.