This set 412403 was released only in the UK and in the NL as far I can find out within a magazine "Lego Discover Technic" Magazine release 3. The fun part of these small sets is that they come without a building instruction in the paper bag the instructions are in the magazine it comes with. However based on the image on the paper bag you can build the set by heart. This one takes a bit of deduction.
I first put all the model parts together that I could see and understand. That left me with just a few parts with which I could easily after 2 iterations construct the invisible steering mechanism. I was stunt by the small size of just 3 studs wide steering mechanism which works even smoothly without the usage of any gears just levers. This designer really had a great day and ultimate form of thinking outside-the-box, I am impressed! Also eye for detail great by mimicking an engine in the back and nice headlights and smooth lines with the flex axles. Great set for kids to play with.