sample or tutorial for conditional pulldown menus

I have a client that would like to duplicate something they've seen on one of their competitor's web sites. It's for an automotive parts supplier and they would like to build a search engine for different make, model, and year applications. Since a picture is worth a thousand words here's a url to see the site they would like to knock off; http://www.performanceproducts.com/shopper_profile.asp?mscssid=2K5UHTRR3UV28 MLG468UVDQR3F4T73P3 They like that you could choose a year and a make, which jumps to a new page with an additional pulldown menu for models associated with the selected year and make. Some models even ask for a submodel. It's pretty cool but it's in ASP and ssssllllllloooooooowwwwwww. I was checking out Hotscripts and Devshed but didn't have any luck. Any info would be greatly appreciated. Thanks, Tom