This is part of the MGM "Crime Does Not Pay" series. It runs 17 minutes and tells the story of crooked used car dealers who are selling dangerous automobiles to many unsuspecting customers.
A young man named Billy Phillips (Darryl Hickman) buys a used car and has a tragic accident that kills his younger brother. A detective, played by Allen Lane investigates.
This is a very well made and interesting little short film that really manages to hold your attention. I haven't seen many of these short films on TCM and I hope they are all like this.
If you come across this little gem, check it out. The rest of the cast includes Roy Gordon, Tom Baker and Cy Kendall.