Yellow is good Rocky - at all times!!! White bad - yellow good!
Draw while in truck is something I often consider - and have developed a belt positioning so that shirt/vest is not captive left or right. That means that while my piece is quite some ways round on right - I can get at it and in fact while driving I often slide rig from 3.30 to 3.00 for better access.
I think apart from a sho rig - seated draw in truck will always be slower but that said - I am glad I rarely drive a car - that is way worse for draw!