I use one of these
http://www.zoro.com/g/Truck%20Ramp%20Step/00042565/I built one some similar to this over 50 years ago and I have built quite a few during the course of time. It hooks over the front wheel. I bought one of these from Zoro a few days ago when they had a 30% off sale. I can't waste my time building one for that price. And that is the only way to get under the hood. Especially the ones with butterfly hoods.