How can I return images depending on users selection?

I have a need to return images based on user selection, the complication I have is the image needs to change three times based on three different users inputs. If I use a car dealership as an example: Firstly I want the user to select a Make of car from a dropdown which returns a generic image of the brand selected, then the user selects the Model of car (separate dropdown) which changes the image to a generic image of that model and finally the user will select the derivative (third dropdown) which shows a specific images of the car selected.
I am using wpmu directory plugin and have tried to get the desired results (unsuccessfully) with Gravity Forms conditional logic.
The potential results are approx. 6,000 images; the first dropdown will have approx. 20 options, each of these will have approx. 30 choices and the final approx. 10.
Any suggestions in producing this would be greatly appreciated.