Dynamic Filters in Idea Forms

In the Ideas form, It would be great if a filter was updated automatically on a field (ie. products) based on the category selected. For example, a user chooses Mobility under the category, only products associated with Mobility would show in the products field. This way, users don't have to sift through the 100s of products -- making it easier for users to submit their ideas. It would remove away from the sub-category as it's pretty useless for reporting. Of course, the Admin would need to pre-load the products per category.