My garage has four doors (two in the front, and two in the back) which gives a lot of cross-ventilation potential, but unfortunately some of the doors had the slide-locks installed incorrectly, such that there was no available slots to lock the doors in a “slightly open” position to let air circulate.   They also only had one lock per door, so I rectified that situation by adding a 2nd slide lock to the other side of each door, and moving a few of the original slide locks so that two of the doors can be locked with a 2″ gap below them.   I spent less than $30 for all four slide locks and a box of self drilling sheet metal screws, so it was a relatively quick and inexpensive improvement.