How it acts when it's started and it's below freeing outside, and then how it acts when it's started after everything's warmed up.

I actually know what causes it, and it's much better now than it was when we got the car. Turns out the stock voltage regulator (a small chip) inside the display you're looking at has poor performance when it gets below about 50F, which causes it to fritz in the way you see here. I soldered in a vastly improved regulator, but used instructions from a guy in California. The chip he spec'd works great right down to 32F, but not below, hence it'll still misbehave on really cold mornings.

It's just the display acting up, and so the car runs fine. Italian electronics at their finest!