Those dicks pinched me at the Mex/USA border once. I only had personal use in my car (AAS). I got a small fine and let loose the same day. About 12 hours in a holding cell. I have aslo had shit siezed and all I got was a letter. Have shit sent to a name close to yours but not the same e.g. If I was Fred Flintstone, I would have my source send shit to Fred Fluntstien. IMHO, it makes denying that the package is in fact "yours" all the more possible.
But, NO, I didn't get any fines or court dates or anything from the siezure letter.