Definitely 110% doable. This is due to the massive amounts of downforce created by the splitter, wings and most importantly, ground effects.

This page has a table comparing the downforce of the original 2011 R18 with the Peugeot 918 from the same year. As you can see in the last column, at Le Mans, the original, 2011 R18 produced 4808lbs of downforce at 200mph. For a car that weighed 2000lbs. That means, that at 200mph, the car would not only be able to drive upside down, but it would be able to drive upside down in an environment where gravity was over twice as strong as it is on earth.

This is not a new thing; the first car that produced enough downforce to enable it to theoretically drive upside down was the Porsche 962c at 300km/h, which was built back in 1984. If fact, at the Porsche museum, they have one hanging from the ceiling to represent this.