The PPG Omni MTK acrylic urethane is what I used. gets a bit pricey after you buy the reducer, harder & flattening agent, but not ridiculous. I was painting a lot of parts under hood as well. I like mixing my own, because then I have one product for lots of parts. I also used it for the top of the dash, but flattened it to something like 20%. I'd have to check my notes on that.
MTK
http://buyat.ppg.com/RefinishProduct...8-CB102B21FA74
Flattening agent:
http://buyat.ppg.com/RefinishProduct...C-8772E7EEFD7D