For those that are building their cars I want to share with you a simple and effective trunk stay I made that a friend named Todd here in Utah showed me. The bracket was made of a scrap piece of 1/8" angle iron bolted to the back side of the trunk hinge. A hole is drilled in the hinge arm that the pin slides into. The holding device is an L handle spring plunger. To lock you flip the spring loaded lever so it slides in the grove. To unlock you pull the handle and turn the lever. The plunger pin I used I think was a 1/4". I may make one for the hood, but it's closer to the radiator. I got the stainless plunger from Reid Supply, 11.79 ea. I think Northwestern is the manufacturer, part #33934, but you have to order it from Ried Supply.
I added a 1/8" piece of steel welded to the hinge arm and ground for a ramp because as the arm moved through it's arch it was to close to the plunger. Each hinge might be different. I tacked welded the nut on the back side.
If you like fabricating things this may be for you. It works great.
ADDED FOR CLARIFICATION
In the locked position the spring plunger mounted on the bracket goes through a hole in the hinge arm locking the trunk lid in the up position. When you pull the plunger lever the pin comes out of the hinge arm allowing it to drop to close the trunk
