Joy Ride (2001)
People talk (on phone in "Black Christmas" and on radio in "Joy Ride") with a mysterious stranger who turns out to be a dangerous maniac.
Rusty Nail played by same actor (and in same way) as Buffalo Bill character in Silence Of The Lambs
DVD seen in pawn shop
The entire episode could be considered a parody of the movie Joyride. The candy cane truck may be related to the main characters' CB handle (Candy Cane) in that movie.
When Lewis slips out of his hotel room to see Venna, parts of this play on Venna's hotel TV.