Yes I do know of an excellent way
Download realplayer from this link:
http://uk.real.com/realplayer/then it can be used to download videos from youtube
a box appears above any video you play on youtube that says download this clip
You can play around wth the settings to identify your prefrences, where you'd like it to be downloaded to ...etc...
Also if you want to turn the video you downloaded into audio for the car maybe, you can use format factory, its a free converter software that you can get here:
http://www.formatoz.com/Hope this helps
Digg