I am currently on a trip from Perth round Australia going anti-clockwise back to Perth. My previous bike rack only lasted till almost crossing the Nullarbor. First up the bolt holding the spare wheel failed as it is only low tensile soft steel. This really made a mess of the bike and I was forced to transport it inside my station wagon. After having that fixed by welding in a high tensile bolt it failed once again on the main support, as has been reported by others so I am now told. Luckily at that stage I still hadn't got the bike repaired. I am presently in Darwin and have had the complete system reinforced. The photos show before and after shots to help those having a go at this modification. I will let you all know how it goes after the long leg down the Western Australian coast. On the "Mark 3 Rack" I got the chap to raise it up a bit so that you could turn the levelling jack handle with the bike still mounted on the back. 

Peter Bishop

The original spare wheel holder ex-factory

The Mark 3 bike rack raised to clear levellers