The Knoxville Police Department has sent out a reminder, saying car theft is usually a crime of opportunity during this time of the year.
KPD reported one-third of all the vehicles stolen in 2018 had the keys in left in them or were left running.
Posting a map on Facebook, the green dots mark keys left in the vehicle while the red dots illustrate the 79 cases last year when the cars were left running.
Some states, including Tennessee, have laws on the books banning you from leaving your car unattended while running.
Across the country, the national insurance crime bureau reports that one in every eight vehicles stolen in 2015 had the keys or a key fob left inside.