Since monday, there has been a strange 'fart' like smell in the car. We couldn't work out where it was coming from so we sprayed the upholstery with Febreeze to try to remove the smell.

We were at the supermarket this evening and I picked up one of the reusable carrier bags from the car boot. In the bottom of the bag I noticed a pack of mozzarella cheese which had burst open, spilling the cheesy brine all over the inside of the bag.

Mystery solved.

The cheese must have been sitting in the car for over a week. The heat over the weekend will have caused the pack to expand and burst. I rinsed out the bags when we got home, so hopefully that will get rid of the smell.