The wheel is hovering over the left pully, under the clock. The little red car can be gotten by pressing the symbols under the golden car, etched on the tablet, I am pretty sure there is a correct order, and that this order is correct. They generally don't show up at the same time, as seen in this screenshot, I just got lucky getting them in the same frame. The wheel will show up in the skull's right eye socket. The little red car will show up eventually, riding the wave of disgestive acid. The little red car can be found by clearing out the moss at the top of the cave's roof.

The wheel can be found at the bottom, in the middle of the screen. You'll need to drag the hanging acorn into the box, next to the hamster wheel. The wheel is right above the fossilised spine in the ground. The little red car will be revealed once you click on a huge boulder in the background, causing it to tumble into the volcano. The little red car can be found by bringing up the green platform, and click the two diamonds in the middle of it. This one is a little more complicated, the wheel is attacthed to the bottom of the third, blue platform. The little red car can be found by pressing all the three red buttons at the top of the screen, on the roof. The wheel is in the corner of the garage. The little red car can be found by pressing the big red button of the crane in the background. The wheel will be revealed to you, once you move foward a bit.

Walkthrough for wheely 7 level 5