Where is this phone number?
 

Some guy has emailed me several times about a car I have for sale, but I can't reply to him because his email bounces (prodigy.net.mx domain)

In the last email, he sent me his phone #: 0115215521062088 - I can't figure out where this number leads.

OTOH, it may be a scam - his emails aren't exactly the most lucid.

Mexico per this link

I think that's a cell phone in Mexico City, just call.
Get the money (cash) then hand the keys to the car... easy. Heads Up: Don't offer any assistance is getting that car accross the border.