There is a black plastic cover under the engine between the two front
wheels. That part came off from its place, got dragged on the road,
torn, and became pieces. There is still a small piece of that plastic
that continues to drag / hit the road whever I reach 60 mph.

I called the local Hyundai. The guy in the service department siad
warranty wouldn't cover that because either the something hit the
plastic part or the people that changed the oil last time didn't
assemble it properly.

He said labor is $90 and then transferred me to the parts department.
Parts department never picked up the phone and I am trying to find out
the cost of the part.

These are my questions:
1) How can I find out the part number and price without having to call
the Hyundai parts department?
2) Is this something I can replace? I can handle moderately complex
tasks, but have never been under any automobile before.

Thanks for your time and help.