Something I always like to do versus Caro Kann players (who aim for a solid middle game setup, is frighten them with this:
1. Castle on kingside
2. Push f-pawn for open rook file on king
3. Push g-pawn if you cant push f-pawn
4. Push h-pawn if you cant push g pawn to push f pawn.
5. Get open lines
6. Mate the black king.
1. You get a strange, wild position, especially in the dreadful Caro Kann.
2. Caro Kann players panic
1. Black should be able to defend if played correctly.
2. You might insult your opponent if he likes solid play (but then again, thats why you pick such a line, hue hue hue hue)
Most fun in blitz.
if you want as crazy but more sound, try either h4 over bd3 or play nc3 and answer e6 with g4.
This is a foolish line. Also after 6.Qxd3 Qa5+-a6 is a well-known motif for black to bore you to death in a midgame or to deny you of easy castling.