I believe the skunk-car is meant to be understood in relation (and opposition) to Forky.
Forky is not a “real toy” but is brought to life through the wonder and love of a human child. This is (I think) a first for the Toy Story series, but suggests that the sentience of the toys is entirely dependent on human interaction of some kind. If a toy is never loved by a human, can it tuly come alive?
The skunk-car may have the nuts and bolts of a real toy, but has (presumably) not been loved by a human child and therefore remains inanimate.
However, this reading does create a possible inconsistency with earlier films where toys still on the shelves of toy shops are apparently able to come to life. Does a toy simply being coveted by passing children enable it to come alive? We simply may never know.