I used anti-static strips when I had a car with tires that caused static build-up, but they wear out fairly quickly. To avoid the problem, I developed a habit of holding onto a metal area of the door as I exit, so the charge dissipates through my shoes with no pain.
Seems like you’ve found a simple solution. Keep it up.
I don’t think tires are often a problem. Working with electronic components far more sensitive than humans, anything less than 35 million ohms to ground is ideal. When I was getting shocks, I found that my car tires presented only 230,000 ohms.
Some car upholstery won’t dissipate static. A driver may handle only plastic while exiting, and polyurethane shoe soles can present billions of ohms. A soap film will dissipate static. I solved my problem by using a soapy washcloth to wipe my upholstery all the way to grounded metal.
Another approach is to wipe the edges of polyurethane soles with a soapy cloth. The resulting film will let static drain past the soles to the carpet or pavement. If you lose your soap film walking on a wet lawn, you may start getting shocks later.