Okay, so, I thought this was a neat question, cause I hadn't even considered using the cars as player sprites. So, I did a couple tests. They work fine in top down as npcs, but I saw a couple different visual glitches when it was a player sprite. If you want to use them for player sprites, they need to be chunked on intervals of 16, so they need an extra 8 pixels on the top so they're 32x32 sprites. (They're also the wrong direction for em, so I made a version of all the cars and mopeds/motorcycle that works as player sprites for easy setup).
I've uploaded the new sprites in the zip file. They're just labeled with "player_" in front for easy drop in. Hopefully this meets your needs, but definitely let me know if you run into any more weird issues with em!