One snag with driving Curiosity in reverse (to ease wear on the wheels) is that the UHF antenna and RTG power source block the view ahead; this left Navcam shot is partly obstructed; the right Navcam has it worse.
NASA description: This image was taken by Navcam: Left B (NAV_LEFT_B) onboard NASA’s Mars rover Curiosity on Sol 650 (2014-06-05 01:51:33 UTC).
Sol 650 raw images (from all cameras), and Curiosity’s latest location map.