Hello again, and thanks for your reply.
I'm glad you don't think there was any way he could have gotten into antifreeze, but if it and/or something like motor oil leaked from under the car, he could have licked it from the floor in the garage.
Dilated pupils may indicate various different things. Toxic ingestion is one, trauma to the head or eyes is another, a stroke, burst blood vessel in the brain or high blood pressure are a few causes. If he's in pain and/or frightened, this can also cause his pupils to be dilated. His vision may be affected, and that's why he was uncomfortable when something was coming at his face.
If his stomach is making a lot of gurgling noises and it sounds like he has gas, this could be due to some non-food item he ingested or he could have bloat, a serious condition in dogs. If his stomach is not swollen, it's probably not bloat, but does bear further investigation.
I'm sure you realize it's very difficult to tell you exactly what's causing your dog's symptoms, without a hands-on examination. I can only suggest some causes, but an in-person exam and lab work will tell the vet more.
I hope you're able to get him to an ER vet center as soon as possible, so that he can be diagnosed and treated. Would you please let me know how he's doing and what the vet's findings are? Thanks!