What is down packed?

When people mis-hear and mis-pronounce "down pat".
Meaning to have practiced or rehearsed something to near perfection.

I've got these skateboard tricks down packed. Dude no, you've got them down pat.

down packed - video

down packed is just a more common variation of its sister phrase "down pat," meaning to have something memorized or perfected.

I practiced parallel parking until I got it down packed.