I recently had my transmission replaced in my 2012 Honda Civic LX. After that, there's now an irritating sound like a socket rolling around behind my dash. It is actually in the middle behind and below the radio and moves back and forth about 5".
Has anyone experienced this?
How easy is it to get the dash apart to look for this irritating thing?

 

Sounds like your mechanic sat something on the dash and it went into the defroster vent. You could try looking with an inspection camera with a flexible shaft. I picked one up at harbor freight on sale cheap and it's a great tool to have. If you can spot what it is, hook up a small diameter hose to a shop vac and see if you can snag it long enough to get it out. If it's something metal, a magnet might help out, too. Happy fishing.
Duane