Well I own two suburbans and Its a total hassle to move the step ladder around the car, plus i feel its rather unstable. I found this, and it looks to be pretty nice. 1000 pound rating, has spring loaded wheels to freely move around the car, and when you step on it it locks the wheels up keeping it in place. I thought I would share. Pro Step Heavy Duty Adjustable Work Platform STK20350 | eBay
I use the werner work platform. It works great for what it is and for only $20 during black friday it was a steal.
The werners are very nice, even so you don't need to bend over time and time again for the guys that are mobile with binned gear.