Yeah, it's a mixing of art styles.
The road, yacht, and bushes all choose not to put very much detail, but the actual cars are all essentially flattened photographs with perfect perspective and angles and shadows.
Not saying that level of accurate detail isn't possible with hand-drawn comics (see pbfcomics for an artist who is simply amazing at choosing the level of detail appropriate for the joke) but the subtle mismatch just looks wrong at first glance.
Then, the inaccurate details in the exact same comic. It doesn't seem like one coherent work with one author.