3m Spray upholsery adhesive is good, it's at most auto parts stores. about as good as you can get without actually working in an upholsery, car audio shop.
The pros I know use a green adhesive, it's mixed with reducer and sprayed through a paint gun, that stuff is the best, but i don't remember what it's actually called, he called it "snot", because that's what it looks like.
The actual proceedure is simple.
Make a board, the surface you're going to upolster. Say, for example, your cargo deck.
block out your text, logo, flames, whatever, out of 1" plywood, particle board, or pink insulating foam. spray down some adhesive, spray some on the back side of your pieces, and when the glue becomes tacky, press the glued surfaces together, and it'll hold forever. THis technique ioscalled "Dry mounting"
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Cover the whole thing using auto carpeting (get it at the auto parts store, or order it from a catalog if you need a unique color). it's thin, flexible, and is used to upholster speaker boxes.
You can also use Tweed, Vinyl, leather, whatever you want, so long as it's not too thick, and can give a little.
spray down the entire area to be covered with adhesive, in a thin, even coat. take a piece of your carpet/fabric, thats a bit bigger than your board, and spray the back with adhesive as well.
Working from the center-out to the edges, press the carpet down, into the cracks and crevices. Tweed, thin leather and vinyl should conform easily, but carpet may need some help. Here's a tip: When your carpet goes around a corner, and wants to buckle like this:
Squeeze the carpet together around the corner, and squeeze the excess together, like this:
Now, simply use a razor blade or similar sharp cutter, and trim the excess off at the corner, using the corner itself as the guide, if you do it evenly, you won't even notice where the cut is, since the carpet's pile hides your cut. The adhesive will hold your carpet down great if you glue it properly (dry mounted).
If you keep the thickness of your design at an inch or less, auto carpet should conform just fine, but extreme undercuts and certain curves will make the carpet want to bunch, in which case, the above technique can be used to remove sags and make it look clean.
once it's all glued down, simply fold the extra material under your piece, or trim it at the edge as I've described. Ta-da! you're done.
Additionally, you can cut "negative" panels, upholster them in a different color, and tack them down in the recessed areas of your piece for a cool, two tone effect.
My advice, practice with some scrap plywood & cheap carpet or vinyl to get the hang of it. Once you figure out how it works, you'll get tons of great ideas & go nuts on your interior!
Hope this helps.