[Nonfractal]

Watched on the rerun.
I can't often make the midnight start ( British summer time) 

1. Courtney's car shudder issue on a proxy car could be:
a. Front axle binding and (as Dennis noted) front tyres too low, too grippy and not trued properly. 
b. Rear tyres not properly glued and trued.
c. Rear wheels badly out of balance 
b. Short can motor in an NSR long can motor mount is permitting the mount to flex causing "ninco hop". 
Mounting the Motor on both sides using a motor adapter/spacer and use epoxy resin to fix the  motor in place will fix this problem..


Dwight's melting track is likely to be a short between the rails caused by a dropped chassis screw. In a short circuit situation, It does not take  very long to create the temperatures to burn your fingers when you retrieve the offending item. 
Often the screw is not found and the short circuit mysteriously resolves itself. This is often caused by the heat causing expansion of the item which is then squeezed and pings out of the track of its own accord, never to be found 

Alan