My idea here is to spread the bags out a little and still be able to carry a few bags at a time.
If you only have 3 or four bags then you can just use the handle section. Over 4 bags you just slide in the extension. and you can carry 8 bags.
The BagHandle is small enough to fit in your glove box.
I'm going to experiment with different materials to see which will have the heaviest weight capacity. I made this one from MDF. The next one will be made from Baltic Birch plywood. I don't think hardwood will be the best option here because it will tend to break with the grain. My guess is that the Baltic Birch ply will be the best material.
Use discretion about how much weight you hang on the BagHandle. I can't guarantee how much weight it will hold.