Brass Monkey car fridge

I have a 60 litre Brass Monkey car fridge. Im finding it has trouble handling Australian summer conditions. They don't appear designed to cope.
When I try to cool it down from ambient, on a warm day, in the shade, well ventilated, it comes up with F4. I have to do this pre cool over night. The store just ran it for a week in their air cond store and said its fine. Once cool, it works okay but I suspect efficency is poor.
I took the cover off and found only a small low flow fan providing any air flow over the small condensor. So, I installed another 80mm fan on the outside blowing air in towards the condensor. I connected it in parallel with the existing fan. This solved all the issues but now I have a fan sticking out the side. There is no room inside rhe case. To replace the exiating fan with a high flow draws too much current. Has anyone else had these problems?