I tried shopping with TrueCar as an end-user (while seriously in the market for a car) and found the experience not very good. I put in the make/model I wanted

I tried shopping with TrueCar as an end-user (while seriously in the market for a car) and found the experience not very good. I put in the make/model I wanted and got a bunch of dealers calling me -- woohoo. Car dealers seem to exhibit cartel-like behavior in various ways, so it seems like it will be difficult to drive real participation in a marketplace like this without proprietary demand (ie buyers at large scale that dealers wouldn't otherwise have access to). The used car market might make a better entry point, because it's actually difficult to fully market a used car as a consumer, and aggregators like Carmax are known bottom-feeders, and their bid-ask spread is too high for the value they provide. Another approach might be to do a hybrid involving car brokers or a merchant model, something more like what Zillow and Stubhub do. If you do this, please invite me to your beta!