This has been plaguing me for years.
I vaguely remember a short-lived cartoon in the afternoon block that ran somewhere between the Inhumanoids and He-Man in the mid-late 80's.
It was a vehicle-based show (or so my swiss cheese memory tells me) that had a protagonist (Jason?) fighting an army of evil vehicles that had some sort of plant life growing from / powering them.
A distinct "villain" was a bullet shaped van type vehicle that had a saw blade suspended on its roof by a vine.
I know that it is NOT Mask or Vehicle Force Voltron.