My shop currently offers automotive window tinting as well as signage. I started my shop a few years ago with my focus being on on business signage. Last summer, my friend's brother, who is an experienced window tinter (3-4 years experience) needed a job. I hired him and I started a campaign to go after the window tinting business in my area. At first, the window tinting business was slow. We joined a local automotive forum and became a window tint vendor, I invested on radio advertising, created a brochure and other printed materials, and we picked up a few car dealerships.
The point I'm trying to make is:
1. Yes you can make money doing window tint. There are months where window tinting brings in more money than signs (tax time, hot summer months). Like any business opportunity, you have to have a plan and execute.
2. You must have an experienced tinter. You are not going to be a good window tinter in 12 hours. The same way that you're not going to be a good sign-maker in 12hrs. It is a skilled trade that takes years of experience.
3. We looked into setups like tint-tek and xpel where you can cut out window tint with your plotter. In my opinion, an experienced window tinter can do a better job. Every car window is different and many of the templates we cut out with our plotter were mediocre at best.
4. Only if you are used to having an employee(s) in your shop, would I recommend getting into window tint. If your tinter is unreliable or quits, you will have several thousand dollars invested in materials with no-one to install it for you. It is not something I would recommend doing on your own in addition to sign-making. There just aren't enough hours in the day to do both.
So, yes you can make money doing window tint depending on your area. But like anything else, it is an investment. You shouldn't just jump into something with no experience thinking your going to make killer money.