My Parts is where you'll find all the parts that you own. From here you can:
◎ Build cars with the parts
◎ Sell the parts for coins or
◎ Use the parts to upgrade existing cars.
Note that you can only use parts to build cars that you do not already own.
Parts are indicated by a riveted metal top left corner. Parts can be used to build or upgrade/tune cars. Buildable parts are indicated by the parts icon in the lower right.