Y'know what is a good idea, I think?

Use the VIN number of your Car!! Vehicle VIN numbers are typically 17 characters. It doesn't change, unless you sell the car, buy a new one, etc.
Use the VIN native as it is on the vehicle until password policy requires you to change it. Then just make changes. Use it backwards. Inside out. Whatever.
The more you use it, you WILL memorize it. eventually.