Really weird expirience while driving in the Australian outback? Can anyone help

Ok. This is a true story, it happened not long ago and was one of the weirder things that have ever happened to me. Me and my boyfriend were driving in NSW, in a national park that only really had a rocky sandy road, red sand everywhere and some bushes here and there. There were wild cows, camels and pigs around, but we only saw the cows. We'd been driving for a couple of hours and i started to smell a really weird smell. I turned to my boyfriend ans asked him if he farted, and he said no, and then asked me if i farted. After we'd established it wasnt farts, we both started to feel really weird in the head. Its a bit hard to explain the feeling, just sorta light headed. We pulled over and both hopped out of the car and stood up, and when i stood up the bright blue sky started turning black, and i almost passed out. My boyfriend said a similar thing happened to him. We couldnt smell the smell at all outside the car, and when we got back in the car it was gone. We started driving, and it didnt happen again. The car was running on gas, but nothing had leaked. Does anyone know what could have happened here? Thanks in advance :D

Were you near a volcanic area? Maybe you drove through a small cloud of volcanic fumes? You guys are lucky you're okay.

Why is this in the ******* chemistry section?
This is why girls shouldent use computers. Back to the kitchen, woman.

I offer two explanations for your consideration:
"Many insects are equipped to wage chemical warfare against their enemies. In some cases, they manufacture their own toxic or distasteful compounds. In other cases, the chemicals are acquired from host plants and sequestered in the haemolymph (blood) or body tissues. When threatened or disturbed, the noxious compounds may be released onto the surface of the body as a glandular ooze, into the air as a repellent vapour, or aimed as a spray directly at the offending target. Defensive chemicals typically work in one of three ways: