A tent against heating up

Now after the winter months I again can devote some time to working on the camper. The first issue is to create a "tent" which provides a shadow in which the van can stand. My idea is to mount a kind of tarpaulin directly onto the camper, which can provide this shadow.

So I get a tarpaulin that is large enough to cover the whole roof. The 4 strong wooden poles, 4 tennis balls, and 4 flag holders.

Here is how this went:

First I mounted flag holders onto the outside of the vehicle.

Then I screwed tennis balls onto strong wooden poles ant placed these poles into the flag holders:

Then came the difficult process of putting the tarpaulin on the roof and attach it to these 4 poles.

And that is how it looks when the tarpaulin is attached:

One problem though: the tarpaulin is very sensitive to wind:

But my method of affixing the tarpaulin is not final yet... I need a way of stretching the tarpaulin so that is is straight and less affected by the wind.