Taxonomy / Advanced Search Issue

Hey Guys,

Does anyone know how to solve the following issue:

I have 3 taxonomy parameters at the moment. Tax1=brand, Tax2=model & Tax3=Reference ID.

They are aimed to help visitors narrow their search down to find the product they are looking for.

Problem: When I use the advanced search widget and select a brand (taxonomy 1), the field where I can select the models (taxonomy 2) updates and displays only the models for the given brand. Thats perfect. However when I then select a Model, the field for taxonomy 3 (reference ID) does not refresh and I have to scroll through all brands & models to find the right ID.

Does anyone know the answer to that problem or have you encountered it yourself?

Thanks for the help,

Hilmar