When I was young I got the windows tinted and this guy recommended this 'Invisible glass' by Stoner because it was safe on the tint (no ammonia or something) and I have just stuck with it for the inside. Using it on the outside is 'okay' but I've started to notice on my windshield the water smears more than wipes off.
Long story short, Invisible glass inside, rain X outside.
I use the soft blue shop towels myself, like 2 bucks a roll.
David Hall - 2009 Pontiac G6 GT Blue 4-Door
Performance: CRABS 03 and FPU, Resonator Delete, RL Strut Tower Bar
Appearance: Debadged - Window Tint 35% front 18% back - Emblem Overlays - Door Sill Overlays