The only good warrenty is the factory warrenty. Take that $2900 and stick it in a savings account, normally I would sujest a Money Market account but with the market right now a savings account is safer and will pay almost the same APR.
It has been my experiance with corporate leased cars that they are driven hard and put away wet.
But with so few miles you should be fine.
Remeber that you MUST use premium gas.
2004 is the best year for these trucks, all the goodies and the lowest miles.