Nice, I'd need 4 since F-ing GM removed the tranny dipstick and you need to jack up the car and remove a bolt to check the fluid level plus another person to add fluid if it's low..
What model car do you have, or rather which transmission? In my 2012 Cruze, I figured out a method to access the oil fill plug without lifting the car at all.
I park on the driveway (A flat, level surface), turn the wheel all the way to the right. I can then crawl under the car behind the front driver side wheel and (just barely) reach the level plug to remove it and check the level while someone tops off the fluid after a drain and fill (using the Rhino Ramps). Much easier than finding a lift or jacking up and leveling the car.
The Cruze has a 6T40 transmission.
Edit: More on topic, I'm surprised at how many cars can't use the Rhino Ramps, according to this thread. In my car, I have to bend the scrape-guard on the bottom of my front bumper slightly to push them into the wheels and pull onto them, but it's not really an issue.
Damn they seem super thin and light to hold up to 12000 lbs!
They aren't actually rated to hold, nor are they ever actually holding 12000 pounds. The rating is for vehicle weight, which means they are holding half that. And if you account for lifting the front resulting in loading of the rear tires, they are holding less than half, resulting in them only really holding less than 3,000 pounds each.