The empeg it self will be fine as the empeg is a small computer which is rare and occasionally difficult to come by the hard drives them selves will not be overly happy mounted at a funny angle but they are pretty robust but if they die they are plentiful to come by providing you have all your music stored somewhere then no probs if it goes down.
Now have you taken your car to a good car installer, as he is very likely to spot a solution that you haven't thought of. If you have been staring this problem for so long them maybe you are taking the wrong angle.
The chevy blaser i imagine is one of american SUV things which will be about the same size as my house i am sure there is somewhere.
I looked at pics you posted in another thread and on solution jumps out at me. The glovebox lid is a lovely flat surface when open bet you could fit an empeg on it. Either you could screw a cage to it and leave the glovebox open with the cage in full view or go crazy with the velcro and cover the bottom of empeg in velcro and just stick it there every time you go somewhere.
You say AC vents are everywhere. Do you run with them all open all the time ? Bet you don't, The centre section vents on many cars can be gutted out and a din sized hole created.
I'm not a pro installer and i have never been in a chevy blaser but i bet i could find a solution, Go get some one else to look a fresh pair of eyes will work wonders
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P.Allison fixer of big engines
Mk2+Mk2a signed by God / Hacked by the Lord
Aberdeen Scotland