Question: what happens if i am a day late on a car payment? 

Answer: Usually nothing happens if you are a day late on a car payment.  Most companies give you a grace period before they add a late fee or give you a 30 day blemish on your credit report.  If you go one day over the grace period both of the things I listed above will probably happen.  To be on the safe side and to get specifics call your financing company.
This question from the Yahoo Q&A forum is categorized in the topic: Family & Relationships