You're trying to break into a tough business, with outdated equipment that won't allow you to compete. That's the crux.
If I was in your position... I'd probably start by making a brand. Not your brand, mind you.
I'd start by picking a local favorite product family (ex. Whiskey!), area, or activity - make sure that it's not anything that would get you sued. Then build social media groups around it. Design a nice, one color, easily weeded logo for the group. Maintain rights to it. Build up a base. Then; start selling the decals. If you're lucky, it'll go viral and everyone will want one. Don't be afraid to be a little cheeky; if you think a lot of people hate your town, make the group "(TOWN) Sucks", if it has a name that can easily be altered to the local derogatory nickname, (ex. Baltimore into Bodymore). Play off of other people's predetermined perceptions that are already rooted in place.
Once and if it takes off, and hell, I'd do 5 or 10 all in the same theme, sell the stickers online AND at local head shops, etc., crosslink all the pages, and profit. Goal is to make a sticker that people want to put on their vehicle.
If you have enough to expand, buy a da** printer and become a real sign company, lol.