PROOF:

His accident in "Make Me A Perfect Murder."
His driving with the man from motor vehicles in "Negative Reaction"
And my most favorite - in "Bye Bye Sky Hi IQ Murder" when he finishes talking to Brandt, and pulls away, we see an orange car, skidding out of control to avoid colliding with Columbo's car. The expression on Brandt's face is priceless!!

Then again, maybe his poor driving skills are a part of his ruse--distract the suspect and get him/her to think he's less than alert.

Yeah, and I always get a kick out of the cop who mistakes it for a heap some guy was attempting to deliver to a closed junk yard in "Negative Reaction", but my question is who, and on what grounds decided it was time to paint dark grey splotches on the side of his car?

I mean, the dedicated viewer already knew Columbo was as haphazard as his mode of transportation, and that's why trashing-out a symbol to the legend of the character to the point of overkill never made much sense to me (although, it doesn't really matter).

In fact, it's that rather unflattering heap that can be seen in the opening sequence to the "Mrs.Columbo" episodes too -- the early ones, that is.

And the way he backs up in A Frined in Deed.

from here x ___---```--__--``` X to here

Frank, that was great. I could here the "sputtering" of the engine in your diagram. Hilarious.