Nothing.
The Rav 4 is solidly built with not so much as a rattle over rough ground.
It is totally reliable and I have never experienced a mechanical failure which interfered with a journey.
However, you have to be realistic about what it will do.
It is not a proper off-roader and I have never expected it to be. Nor is it a hot-hatch.
However it is a good mix of both. It handles well and is quick off the mark on the road for a 4WD, but chunky and robust enough off the Tarmac if you stick to light towing duties (small boat/trailer). A caravan puller it ain't!
It's worst aspect is lousy fuel economy, which in the UK with unleaded at £1.45 a litre, can be a problem. But then, only an idiot would buy even a small 4x4 like this and expect anything other than than the aerodynamics of a house brick!
£1.45 a litre I know we have europe's most expensive fuel, but that's stupid its only 69.9p at litre at sainsbury's.
I was thinking the same thing, must be a new mixture of unleaded and liquid gold your feeding your rav :)
Yeah, 1.49 is pretty steep!