Fair enough on the no doors for the summer.  But I wear glasses with the transitions so my lenses don't cover the side like a strictly sun glasses do.  So I would like it to match my back windows and help with glare.  I had 5% on the front 2 passanger windows of my 99 Dodge Ram, and 5% over the stock 20% on the back and I would never look back at doing it again.  People can't see in to steal your stuff, reduced glare, and it looks better honestly.  I only got pulled over 2 times in over 5 years of having it on the front here in ND.  The legal limit in front is 50% also  

  So I think 20% is a little compromise, and it will match the back, or so I hear.