I do carry 3 spray wash bottles in mine (diluted car shampoo, distilled water, and 30% Vinegar/Water) and have never had a problem with them. However, I do carry them on the sides of the storage area. Any materials that can I might need that can go soft, such as assembly lube (for screw threads) etc., I double bag in Zyploks and place in my tool bag.
Don't put women's cosmetics in there - they will melt down.
I only use the compartment to transport materials for the car - tool bag, wash fluids, car cover, etc. - everything else goes in the passenger area.