IMO, last click or not, until consumers can actually purchase cars online, it's simply going to be too difficult and convoluted to assign a dollar value to specific digital campaigns touch points. There's your major difference between e-commerce's ability to more easily justify digital spend...you can click and buy. I think a wise metric to look at is total site/VDP traffic and total in-market buyers in PMA + radius. If that ratio is low, it's going to be tough to expand car sales. It's a good measure to see if you should increase spend digital or re-focus efforts.