the tinit definitly goes on the INSIDE. if you remove the windows it makes it easier to tint. i always used a cheap snap-blade utility knife found at the dollar store taped to a bic pen to get an even cut around the outside edge. 35% is a decent tint. i used it on my honda accord and nobody said anything until a state trooper with an attitude made me peel it off right there but that was almost 2 years after i did it. make sure you clean the window throughly. and be patient. anything and i do mean anything left on the glass will show up on the outside and make a tint job look like crap!!!!!!! i know i've seen me do them numerous times.
the film will want to "run" or lift esecially around the four corners of the glass. i use a warm soapy water but dont use alot of soap. let them sit for AT LEAST a day in a warm sunny area. be careful putting them back in the vehicle when they dry. good luck