they sell some spray adhesive and you just wrap the panels with the vinyl. i was thinking of doing it but im not sure.
If you do get a heat gun it makes it easier to mold it around. Also go out and get some MEK (methyl ethyl keytone). What you do is pour the MEK on the polyester backing let it sit for a few seconds and then the polyester backing will start to seperate from the vinyl. Then you just have to pull the backing from the vinyl. This makes it so that the vinyl can be wrapped easily around the curves and makes it flexible. Just let the MEK dry before you try and glue the vinyl to the sides.
Look at this it looks like his bottom tray was done in vinyl it looks really good! http://www.mmb.maverick.to/attachment.php?attachmentid=35945&d=1249509090
Wow that's real nice. I really like that whole dash. It looks almost like it's vinyl too. About how hard is it to get the dash out?