I too have a 1989 4runner.
I have vinyl covered plywood rear panels. 6x9's sound much better.
I like pirate for how-to stuff on the mini trucks.
The window switches get dusty. Like I tell my wife, "Hit the button like you MEAN it."
then the window switch works. It is probably just dirty.
Craigslist and the junkyards are the best part sources. Lots of parts interchange on the mini trucks.
Take the top off and enjoy it!