Passing Mail Tags to upicrm

Hello, I’m trying to setup upicrm with Contact Form 7 and Car Dealer Theme from Potenza.

My forms are working properly, but there is a field I cannot get mapped into upicrm that I need. On the Mail tab in CF7 there is a mail tag called vehicle_details. It is not being submitted to upiCRM when a form is submitted. Is there a way to pass that to upicrm? The user doesn’t fill out this field, it is passed from the page somehow.

Thanks,
Rob