I have a big grocery basket that attaches to my rear rack, so it has a large flat surface. The eggs at our market aren't refrigerated. I usually bring my own cardboard cartons and put the eggs at the bottom of the basket and stack flats of berries, meat, vegetables, etc., on top of the eggs. It's only 1.5 miles and mostly flat to/from my house to the farmers market, but our roads are pretty rough, so unless I ride super slow (<6-7 mph), everything bounces around. Would bungee cords work, or would the eggs still break from bouncing in the cartons?