Sometimes VRM does not pick up the correct vehicle details. This often happens when a car has had a plate change, but sometimes when the VRM has incorrect data. It is useful to check with DVLA on the Check MOT and Car tax page that the vehicle is showing there.
When the vehicle details are incorrect also check you have the correct Registration.
Once you have confirmed with the customer that all is correct go to the model showing and click change. A box will appear for you to manually input the vehicle details. Any fields that do not have any specs can be manually added by clicking on the + button next to the drop down box and input there. carryon down to the bottom and click OK.
NB. If the customer is a new customer, its advisable to create a customer record for that customer first before doing the VRM or manually inputting the vehicle details. Then when you go back into the customer record, you click on the Vehicle Icon. and then follow the steps above for building the vehicle.