My Prius was stuffed with trash yesterday... spring clean up. Last weekend was the same story... a trap and lots piled into the Prius. I've carried a few serious loads of cargo from the hardware store too. Being a large hatchback makes it extremely practical.
Here are some more Prius haulers! http://priuschat.com/forums/gen-iii-2010-prius-main-forum/90008-example-prius-cargo-capacity.html
I have NOT used our Prius that way, but..... I used my 84 Plymouth Horizon (gutted for drag racing) to carry 40 bags of 40 lb marble chips that were on sale. They were stacked up to the should line all the way around the interior, 1600 lbs. The day before yesterday I picked up 70 cement decorative patio blocks that weighed 20 lbs each in my 05 SRT4 Neon, 1400 lbs. I used to use my 3 banger Geo Metro to deliver rims/tires that I used to sell (still sale rims) and it could carry a packed 840 lbs...4 245x45x17 on 9 inch rims and 4 275x40x17 on 10.5 inch rims....two beside me where the passenger seat was, three laying down pancake style behind me where the rear seat used to be, 2 more sitting upright beside those, and one in the hatch. Every 100 lbs was 1 mpg less.
