Hey Steve, thanks for the welcome and the quick reply.

Are you saying that with the page save/load you mean when physically entering the data hit the save button after that field? Or, are you suggesting that onChange I do something like an ajax call to save?

I’m hoping for a code based solution and have just been mulling around ideas. I’m new to Piklist so every idea requires a lot of hunting. A few thoughts I had:

1) Add data attributes to the option field and use jQuery to hide those in vehicle_model select that don’t have the parent ID of vehicle_make. It looks like I’ll have to hack the code for that though, as I don’t believe we have the option to add attributes with the Piklist metabox fields?

2) Possibly writing a custom filter? I haven’t read anything about extending Piklist yet so I’m not sure how hacky I’d have to get with that.

3) Breaking up the make_model taxonomy into two separate taxonomies with some type of relationship via custom fields in them. Then I’d just using them in the standard sidebar like tags/categories. Not sure what kind of problems that would cause down the line though.

Thanks again Steve. Hoping I can figure something out. This is my first foray into Piklist and I’m planning on using this as a springboard to several other projects.