I wanted to have a side window installed in my Nissan Cargo Van for better visibility when backing up and some more ventilation as well.  Apex cut out the metal portion on my sliding side door and installed an aftermarket window with two small sliding windows across the bottom with screens.  It looks perfect and I get compliments on it all the time.  Drove to Texas and back through some horrendous downpours and never had a single drop of water come inside.  Highly recommend for any glass work needing to be done on your car or van