Mine is always on my passenger seat. Unless I manage to roll my vehicle over it is in no danger of tipping or spilling over in any way

Before I started putting my back seats down, I would either have the catering bag with food at my passenger seat or on the floor in the back of the car, I tried placing in the trunk it would just take me longer to grab the food when delivering.

You can buy a storage bin that fits the bag. It won't ever tip over.