Please note, as with all sports, you can only watch NASCAR live. 

NBC Sports Live Extra

This can be found under Videos > add ons

You can access quite a bit of live game coverage for NHL, Premier League, College Basketball, NBA, MLS, NASCAR, MLB and Golf.

Sports Devil

Go to live sports > First FirstRowSports.eu (or FirstRowSports.ge) > Motorsport

or

Go to live sports > Zunox.hk