Menu Items & URL Rewrite issues
The Cars List Module is often published in the Home Page of your website and it's useful to go directly to the details page of a certain car. Configuring the module properly is important to avoid issues with the active Joomla Menu Items and with the URL Rewriting functions.
If you have problems with the Active Menu Item after selecting a vehicle or if the details page is never displayed, then it's because the parameter 'Default Menu Item' of the module has not been configured correctly.
Click the Modules Manager page in the administrator section of your website and edit the parameters of the Cars Module 'mod_vikrentcar_cars'. Make sure the parameter 'Default Menu Item' is assigned to one page of type 'VikRentCar - Cars List' of any Joomla Menu. This should fix all the problems related to the URL Rewriting and to the Active Menu Items.