Other mistake: The RV's cassette player has some odd features (some of which I've never seen on a cassette player). There's a "push button" for "loudness", not "volume." There is another "push button" labeled "MO ST" - not sure what these mean. The slot for the cassette tape looks wide enough for a VHS tape. (00:11:15)
Suggested correction: There's nothing wrong with the stereo. The cassette slot is the normal size for that configuration on an 80's cassette car stereo (they're in an '87 Suncrest). The loudness button was also a common feature for that era. It boosts low and high frequencies at lower volumes (the stereo still has a volume knob). MO stands for "mono" and ST stands for "stereo."
The slot looked way too wide, even for the 1980s. I would have guessed that the "ST" meant stereo, but wouldn't that be referring to the AM/FM radio, not the cassette player? (Thanks for the "MO" clarification). [Features were still on the odd side.].