Mold of dash trim

This might sound stupid to some people, or hell, maybe everyone, but what I am wanting to do, is in my 1999 Nissan Maxima, I am wanting to get some liquid foam, and pour it into a rubbermaid bucket, and then setting my trim in there front facing up, and not sticking it all the way in there, just a right to the top... then once it sets and dries, come out and pop it out(not sure how I should do it, if I need to wrap it in Aluminum Foil or tape before setting it in there) and then filling the mold with liquid plastic, because what I will be doing will be mounting my aftermarket HU down where the little pop out drawer is, and installing a screen where the factory HU is, does this sound like it would work? I was going to cover the top of the trim with tape or foil, but then I started thinking about how I would attach it, if you have ANY ideas what so ever, please help a new fiberglasser out please, just tryin to make it look factory and look awesome... The reason why I don't just get the dremel out and go to town on the factory trim is because if I want to sale the car or trade it in later, I can have all the stock stuff, and bolt it right back on. Thanks for the help, and please help if you can, no idea is stupid at this point. Thanks. I love the 12-V!

And not to mention way less work by just buying extra parts from a junkyard, it will be a lot quicker that way.