Other than the fact that it is illegal (in Canada) to have a tv/display in the drivers view or line of sight, or visible from the driver position.

Just make sure you take into account:
power - you will need a fair bit, unless you bypass the ac/dc converter in the PS - not easy, but it has been done.
line of sight from you - make sure that you "cannot" effectivly see the display(s) - or make it look like you can't (nudge, nudge, wink, wink.....)
storage - will a PS really fit into a civic's glove box?
what about a vcr? dvd? etc.... the possibilities are endless (so can be the cost!)

Have fun!