JCD, if you haven't tried this, I suggest you do.
wash and cut yellow squash into 1/2inch or less slices, place on foil, sprinkle with salt, garlic seasoning, pepper and if you like hot pepper, add a bit of that.
chop a medium onion and put that on top of the squash.
toss in three tablespoons of butter.
close foil, airtight, put on grill.
even if you don't like yellow squash, I bet you will eat this.
It is one of two ways, I can get hubby to eat yellow squash.
note: you can add chopped green and red peppers for color and flavor.