Odometer doesn't progress mileage when combo meter screen turns off.

Hey everybody, been using this site for research for quite awhile, and finally created an account since I can't find any reference to this specific issue.

My girlfriend's 2008 Prius Touring has had the dreaded combo meter cap failure issue since October 2023, causing the screen to go black intermittently. Sometimes we're able to get it back on with the headlight toggle trick, sometimes not. It really hasn't been too much of an issue for her, it bothers me but I unserstand why she'd rather get it done professionally. The dash is pretty sunbeat, and those plastic pieces tend to disintegrate as soon as I touch them.

Anyway, point is later this month we're taking it to a guy in Dallas that replaces them with a refurbished/upgraded part for around $300, not a bad deal. The big selling point for me is that he's also able to copy over the current mileage. However yesterday after driving over to her parents house, I happened to clock the odometer at exactly 151,000 miles before she turned it off. When we left that afternoon the display was off again, and remained off while we ran errands around town. After the last stop as we got in the car to go home, the CM came back on this time and it was STILL at 151,000 exactly. We had driven probably at least 30 miles since leaving her parents, and now I'm wondering how long this has been going on.

I haven't seen anyone mention this happening on this site or any other site I've done research on, and I've read through quite a lot of people's experiences with this. My question now is, are there any other systems in the prius that record mileage other than the combo meter? I'd like to have an accurate mileage when we get it replaced if possible.