Vehicle features can be attributed to any of your vehicles. They are displayed in the booking form when the user is selecting a vehicle as shown in the image below.
Vehicle features can be added in two ways:
In the vehicle edit page
On the vehicle edit page there is a small Vehicle features metabox. Here, you can either link existing features to the current vehicle or you can quickly create new ones.
Vehicle Features page
Alternatively, there is a Vehicle Features page which can be used to manage all features.
On this page you can also add descriptions for features which will be displayed when the user hovers over the feature on the booking form.