does it absolutely need to be a bolt on underhood light ? i remember seeing a plug into your cigarette lighter["power port"] deal that had a magnetic mount as well as a swivel [leg type] support that you use to aim it where you want. i think it was advertised in a camper supply catalog, and it was pretty reasonable price wise. or even one of those "snake lights" ? i have one of those my wife got me, and it comes with a lighter port plug as well as a 110 plug for recharging. it's light is pretty dang bright and the magnets are very strong and will clamp to almost anything, allowing the flex head "snake" to properly position to light up whatever you need to illuminate. just throwing out a couple of options you may want to consider.

My 70 D100 has one but I don't think it is original.

http://www.amazon.com/dp/B00AYNQQNS/ref=...=I1MIZP23W87DSB


This plus a tie wrap or two fastened to underside of hood is the best that I've come up with.

This is an excellent general purpose light. Owned for 1 year and still impressed with it,

Great stocking stuffer gift for your car buff or handyman pals.