I have actually coined this "The Never Ending Waterfall" and that says it all. The drive here is spectacular as well in the remote Mjóifjörður which means the narrow fjord.
Though the road to Klifbrekku is not officially an F-Road, I still HIGHLY recommend driving only a large 4x4. The road is steep, winding, bumpy, and narrow. In the winter, the road can become impassable. There are no water crossings to get to Klifbrekku.
If you want to play it safe and be in a well-equipped, photogenic car, then you should rent an old-school Land Rover Defender from www.isak.is. Use the code "gunnar" for renting your Defender on a special price.