Marketscan, Cox (AIS for incentives and Dealertrack for RVs/MFs) and Chrome are the only players in this space but Chrome doesn’t have all the non captive data yet and I think they are a couple years behind the other 2. Marketscan has been the leader in this space for a long time but Cox has caught up. Marketscan is a web based desking tool or does payment calcs through an api. Cox and chrome are entirely an api.
These companies license access to these web tools and apis for large annual fees or per call hits to their api. The only ones that can afford it are the OEMs, lenders, and the automotive data and digital retailing companies. Most use it to quote payments on specific applications. They don’t license it to consumers directly or to sites that will expose the main components (MF, RV, inventive, acq fee, etc.).