I am trying to bring back shine to the dead paint on my truck. It is 10 year old single stage yellow paint that has been neglected for the past 5 years while the truck was down. I have buffed the truck with a high speed orbital buffer and Meguiar's #2 Fine cut cleaner. The shine is back but there are some spots that are cloudy or somewhat dull I guess you could say. I am afraid to continue buffing those areas for fear of burning through to the white base coat. I'm not sure whether it is dead paint or just dry paint in the cloudy spots but when buffed long enough they do go away.

Question now is: What products would you recomend I use to finish out the trucks cloudy spots and also protect the paint when completed? Also, is a clay bar necessary or useful in this application and what is it's purpose?

Thanks for any input guys!

Clay bar would have been an earlier step. The fact you've compounded the car (rubbing or polish) means you've surpassed its effectiveness. (anything that WAS on top of the paint is either buffed off or buffed in )
Dull spots? Depends on what your using and how long you've stayed on them with the buffer/ polisher. Are you using a foam pad and about 2000-3000 rpm? or somehing else?
I like 3M's "finess-it" line......number 39003 or 30093 something like that. They call it Machine polish. Its expensive at about $14/pint but it works.