/diy/ - Do It Yourself

I'm looking to build a motorcycle phone mount but having trouble thinking of an easy way to lock the phone in the enclosure.
The idea is it has a lid with a hinge that you open up to drop the phone in and it locks in place when you close it, any ideas?
I've got magnets but that's not enough and my other idea is a bolt with a spring that you pull back and it unlatches but thought i'd see if there's a better, more elegant way. Maybe one that doesn't require a spring.
Here's my very technical draft.