Edit: After investigating a bit more, it seems that the only cars affected are the only ones with .xml files in my ELS folder. They are fbi buffalo, LSPD cruiser and buffalo, and sheriff cruiser and SUV. One of them is in all caps: POLICE.xml, and the others are all lower case (fbi.xml, police2.xml, police4.xml, sheriff.xml, sheriff2.xml)
Is this my problem? Or is it something I need to fix within the .xml files?