The truck driven by a character to the line is clearly in park instead of in gear.
Hair and clothing styles do not represent the period the film occurs in. The show designs and colors in particular are more modern and representative of post-2020 designs.
The lawn mower is obviously not from the correct time period. It is newer than 2000, based on the engine cover design, the exhaust port with a spark arrestor and the newer plastic parts on the case itself, that would have been metal in 1989 or before.
The flooring at the motel is gray tongue-in-groove imitation wood flooring, which was not in style nor would have been used in motels at the time period represented.