Go to the forms tab under 'Settings'
From here you can create forms for the Vehicle Detail Page & see the inventory hooks for Gravity Forms
Add the desired fields to your Gravity Form(s) with the corresponding hook as the 'Parameter Name' under 'Allow field to be populated dynamically
To capture vehicle information you will create additional text fields. You can either use 'Hidden' fields or 'Single Line Text' fields. We prefer the 'Single Line Text' field so that you can see the data on the page for testing and then mark the 'Visibility' to 'Admin Only'. (See screenshot below)
Note: you can find the inventory data hooks in the CarDealerPress plugin under 'Settings' > 'Forms' (See screenshot above).