This is interesting because as a car buyer, the only experience I want is car sellers quoting me prices until I get the lowest one. All via email.
In reality, even very desirable cars can have this game played on them. I once sold a car $25k over MSRP, and the customer was thrilled because that was the lowest markup he could find.
When it comes to used cars, finding the lowest price is usually a terrible plan I could go into for longer than a PG blog post.
By far the swiftest and best large product purchasing experience I ever had. I was sad to see them close.