Volvoman, here's the link Smart Hauler Ramp System for loading a Smart Car
They rate them for 2,000 lb per axle, they are certainly built robust enough to handle a Smart. Few things you need to know, Smart has a varied width between tires, rear tires are further apart than the front tires, which means that with 12 inch ramps you do not have much room for error from side to side going up or down. Positioning the deck anchor points is critical and a spacer bar to keep them parallel at the bottom is essential. That said many people use these ramps without problem, you just have to pay attention and correct the track the car is taking with the steering wheel (split the difference). Discount ramps sells Big Boy ramps which are 16 inches wide which allows you to be "more sloppy".
Note that the ramps are available in two heights (40 inches and 44 inches). Typical Volvo deck will be at 45 inches (with the suspension up), dumping the suspension will lower it 4 inches. I am not a great admirer of "air dumpers", folks who dump suspensions to hitch or unhitch or to load or offload the Smart. It introduces all kinds of issues having to do with safety, skill levels, forgetting things, etc. There are ways to hitch and unhitch and offload and load Smart safely, without screwing around with the truck suspension (my opinion and I'm sticking with it). To do this you would need the 44 inch high ramps.