The rear canopy seat is a cute idea, but I wouldn't consider letting my 7-yr old ride back there for any reason...

...that's what the four-door MBs are for...

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car