c-clips are no problem, if it would be, there would be an upgrade already

mayhem is nicest RTR with good radio but real legal races use .21 motor
nice to work on and robust, no need really for many spare parts

screws are now locktided, just check all and see specialy into those who guard the little rods in between the towers, radiobox screws
and check regulary all , you have to do this with every buggy anyway
better put 16 mm. screws and nyllocks at the steering rack turn points

clutch should be fixed now, if not, you just have to buy black mugen shoes or the new metal ones of mayhem, springs are ok
you even get free new ones if you notice Horizon you got bad ones