Yes, these include a maximum limit of 500 km that the car can be driven prior to you returning it, and a limit of 3 returns per household in a 12 month period.
Additionally, if the car is involved in a major accident or is written off then it may not be returned.
You can view the full terms and conditions of the Carma 7 Day Guarantee here: https://carma.com.au/ts&cs