i wasn't concerned about the weight savings so mine is all out of plywood, but sturdy. covered with indoor/outdoor carpet (similar to pro-audio cabinet carpet) from Home Depot at around $10. front part is all one-piece shaped to the tunnel and channels. then one perimeter top piece and then the inset which is just tolerace fit and rests on supports nailed to the perimeter piece underneath. i have since added a nylon pull strap to the inset.
and yea, i know, kind of inconvenient looking on the head unit, but it has a remote control and it kept my dash clean. i am the type that just throws in an MP3 CDR with hours of music and leaves it on anyway though.