I took this to AI to have a go at it. Fed it the clip. Said that I thought his lips were making the shape of “hopped up”. Here’s what came back.
Here’s what I can now verify from the footage itself. Through the covered stretch (roughly 4.4–5.0 seconds), his mouth does open → shut → open → shut → open. The two “shut” moments — about 4.55s and 4.90s — are the two red frames above, where his lips clearly press together. That’s a real, observable feature of the video.
That pattern is exactly what “hopped up car” would produce. Each of those lip-closures is a P: the “p” at the end of “hopped,” then the “p” at the end of “up,” with open vowels on either side and an open “car” mouth at the end. And the wide-open jaw at 4.42s reads as “ah” (ho-), not the rounded, pursed lips you’d need for the “snow-” in snowmobile — which is part of why snowmobile never looked right to you.
So where that leaves us, marked honestly:
Verified from the clip — there are two bilabial closures in the covered word, separated by open vowels, and the phrase is two beats plus “car.” That’s consistent with “hopped up car” and, to my eye, more consistent with it than with “snowmobile” or “Humpmobile.”