What are some free add ons for a car?

These original models were criticised by many people for being inaccurate. However, as with Microsoft Flight Simulator, people started creating and distributing their own models and other content through websites. The quality of these add-ons is often much better than the originals. New routes, trains, sounds, cabviews, and other MSTS accessories are available either as freeware or payware from various websites and companies.