Fuel Type filter fixed in Recents API - fuel_type and other taxonomy filters were failing for recents API, They've now been fixed and filter results correctly.
API Release - v2.2.0
Search by MSA code, city and highway mileage search, non-VIN listings, full text search for RV, motorcycle and heavy equipment, and MPG in the basic decoder.
API Release - v2.4.0
OAuth 2.0 authentication, Cars Recalls API, Cars Cached Images API, and a deprecation notice for the source and dealer_id search parameters.