I guess my experience with the Ranger baseplate set me up for a false expectation. The only thing I had to remove on the Ranger was the two front tow hooks. And no drilling, it all just bolted on. On the Smart, I literally had the entire body off, from the quarter-panels forward. The worst was drilling two 1/2" holes through a steel box-frame member on each side, while bending the plastic wheel well out of the way because it couldn't be removed without disassembling the steering linkage. But to be fair, at least removing body panels on a Smart is do-able. In fact, I believe you can buy make-over kits on Ebay, where you change the color of your car for a quarter the cost of painting, by entirely replacing all of the plastic body work! So don't mind me. I'm just grousing.
And I should report that the Roadmaster instructions were excellent and all the parts fit perfectly.