i can only speak on my experience with tint. Don't cheap out on brand, Llumar is leaps and bounds better than most of the tint on the market. I went cheap and got the mid grade 3M tint as part of a pre-cut kit on eBay, needless to say it's now completely clear after 2 years. I had Llumar on my car before and it lasted for 8 years, i just wanted it darker so I removed it and got the 3M kit from eBay for $80 shipped (big waste). if you can get a pre-cut kit from ebay using Llumar, go for it. trimming your tint is not that difficult if you can't find a pre-cut kit or if you just decide to use a roll. key to trimming correctly is a good Olfa style blade. shrinking tint takes patience especially if you have never done it. 2 keys to shrinking tint, lots of patience and a good heat gun. next is the application of the tint, this is probably the easiest part as just use a lot of solution to help position the tint. they got a guy (looks like he's 12) that has a youtube channel (tintstuff) and does a phenomenal job tinting, makes it looks like a chic can do it. after watching tons of his stuff I have since tinted a few cars (all my own) as well as added some additional tools.
I figured that part was over looked so I thought I wold help you out a tad lol.
I couldn't imagine having tint on the outside part of the window...would be tore up in a week lol
there are guides all over the internet, but i tried before and it is REALLY HARD. hardest part IMO is when you roll the window back up and have to get it inside the rubber gasket at the top of the window without having the gasket lifting up the edge of your film off the glass.
every time ive had my cars tinted ive asked them to pull the door panels off and run the tint an inch below the gasket/scraper thing. never had any place refuse and i always gave them some extra cash for the work. bonus with doing it that way is i never had to wait a week for my windows. just had to wait a day. oh and the ONLY tint that might ever possibly be put on the outside is the sunroof. all others go on the inside after being measured on the OUTSIDE. :-)
idk if its harder or not. i just kno it takes about an hour longer to have them do it. but ive been goign to the same place for 10 years. they will tint my entire windsheild and then do the legal "strip"
ive done mine before never will again i bought it pre cut and did it its a pain in the *** better off to just pay 100$ and get it done lol
lol its not even hard at all once you get the right tools you'll be succesful. if you want good tint window rolls visit WindowTint.com they have good prices
Buy tint in a large amount and practice on your friends car. That's what I did and if you have laid vinyl on a car before its simallar to tint soap and water then Squeegee the water out. My first time was rough. I also find it easier and longer lasting if I remove the door panel and get below the trim
some people are just lazy/ or fail at doing things and give up quick.
White dragon has it right but measure inside I tried outside and came up short. Trail and error find what works for you. Just remember you can try and if it ***** remove it clean it and try again.