1. Actually mobile traffic accounts for about 66% of most dealers traffic now, at least those with a proper marketing strategy. And this is why you have to have Google Signals activated in Google Analytics to make this work. It's possible to link cross device traffic with identity resolution, it's not entirely one to one.
2. Dealers should count service customers! That's at least half, and often more, of a lot of dealers profits. It's not hard to separate service from sales if you know what you're doing.
3. They are not going to count service customers twice. Google knows how to filter dupes. They do it the same way they filter employees.
4. Be-Backs will be filtered like all other dupes.
5. It's possible, but Google has the ability to minimize this with identity resolution that can filter at the household level.
6. Test drives are not going to be counted as multiple visits for all of the reasons mentioned previously.
Proper UTM tagging will identify a source, but it still has to visit a dealer's website and their lot to count as a store visit. Store Visits will track referral sources from all referral sites, doesn't matter where they came from. Third party listing sites are going to hate this because it's going to show the dealers how effective they really are, or aren't... and it's going to force third party sites to prove their value beyond the BS they provide dealers now, and that's what they're going to really hate. This is one of the reasons third party sites do not want to send traffic to dealers sites, they suck at that. Third party sites want to BS dealers into thinking they are generating exposure that drives conversions. But now dealers are going to have a choice, spend their money with vendors that drive customers to their service drives and that buy cars, or exposure and hope it does something. Smart dealers are going to invest with vendors that they KNOW will sell cars and service.