You should. I have that (of course I make them too), some samples of my window decals, & a qr code for those who are connected to use their smart phones.
I get plenty of comments on the decals & pass out biz cards all of the time.
You can include your number if you'd like, that's a personal call. If it applies to your shop, do so.
If you're interested, drop me a note. They aren't hard to put on really (I'll forward a copy of the instructions if you'd like), especially not the qr code, it's as simple as a sticker.
But get out there! Let everyone know who you are. People walk past & drive behind you all of the time.