I never had a car runner, but I did share the habit of gnashing my teeth to music stuck in my head. I’ve modified it to clicking now.
I also have a strange “thing” with even numbers, especially 4 and multiples of it, except for those that end with 6, with 16 being the exception to the rule. Didja catch all of that? For instance, the volume on my car stereo can go up to 50 before most others would consider it loud. That gives me a lot of numbers to work with. When I adjust the volume, it always has to stop on an even number, unless it ends in 6. If the volume level is comfortable on a number that ends in 6, it’s acceptable to set it one down, so the number ends in five (which is the only exception to the even numbers rule) but never one up for a number ending in seven. If someone else adjusts the volume, I have to check and make sure it’s on an even number. If it’s not, I will adjust accordingly. My son has actually taken note of this and will always put it on an even number. He must think I’m a freak.
I think I’m a freak.