Supercharged Light Rhino SUV may appear at heat levels 3, 6, and 9.Sergeant Cross will not appear at heat levels 5, 6, or 9.Spike Strips may appear at heat levels 3 and 6.Heat levels 6 through to 10 can be initiated in career mode and challenge series events.Mercedes-Benz SL55 AMG - (Uses Mercedes-Benz SL65 AMG mesh).Mazda MX-5 (NC) - (Uses Mazda RX-8 mesh).An optional 2 work-in-progress vehicles.Multiple traffic vehicles and PPD units can be unlocked through the Challenge Series.Their Stacked Deck cars can also be driven in Quick Race.Angie's Dodge Charger R/T, Kenji's Mazda RX-7, and Wolf's Aston Martin DB9 can be found in Custom Cars without having to acquire their pink slip.The Improvement Mod has a long list of additions, alterations, and general quality of life fixes included with its downloadable zip file, but here's a few highlights