The solution for squished sandwiches?
A Sandwich Tin! This is a metal box about the size of a piece of bread. When you use a soft-sides lunch carrier, or even a regular lunch box, you can put your sandwich in here to keep it from being squished when packed/shaken around on the way to school or work. It also keeps it fresh & you don't use energy by throwing away tons of baggies. It's a pretty handy item.
The square tin has close up/off the edges winking forward-facing classic Sonic for the lid & a blue/white checker pattern for the box base. Sadly, it also has "Faux Wear" or the purposeful design chipping to make it look 'vintage', but generally comes across a bit shabby instead. This is a 2016 item, but where could it be found?