2004 Elantra Vibration in lowest gears

Just had all the engine mounts replaced in our 2004 Hyundai Elantra with 115,000 miles. Something new has emerged: When stopped with the engine running, there is a loud vibration in Drive, Reverse and Park, but not in Neutral. What do you think is up with this? Thanks for any advice/insight.

I would take the vehicle back to the shop that did the engine mount job. Sounds like they may have made a mistake when installing the new mounts. It could be the mounts or it could be the exhaust system touching the frame.

Thanks. I did take it back and they said everything looks good. Didn’t ask about the exhaust, though. Additionally, I’m ready to have someone else check their work. What do you think the chance is that it’s the transmission?