Here is a close up of the locking mechanism we came up with. It is made from stainless and the pivot points are designed such that the mechanism will always fold up the right way when the front is closed.
The bottom hole (with the bolt in it) is the pivot bolt. The upper hole is there for a push-pin to lock the mechanism (and the front of the car) in place. The push-pin has a ball detent to keep the pin from falling out.
You can also see a close-up of the split engine compartment panels.
