This.
I've been in a few accidents and have been beaten by my belongings and had my shtuff flung all over the roadside.
My father-in-law took a toolbox to the head, launched by a rear-end collision. 25 years later he still has cognitive problems and a plethora of medical issues.
Secure everything you can. In an accident your unsecured gun becomes a bludgeon, or at best an escapee.