Land of Black Gold: How did Snowy travel?

On page 16 of The Land of Black Gold, Tintin is abducted by the Arabs to be taken to their leader.
When they released the gas to make Tintin and the policemen unconscious, Snowy ran away.
But in the next few frames,Snowy is seen following the kidnappers who are boarding their car.
So, how did Snowy reach their destination?
He surely can't have gotten into the car, or else the kidnappers would have seen him?
He also hadn't latched onto the back of the car.

So - how did he travel?

Rocket skates...? ;-)

This seems to be an error that was introduced when reworking the pages for the colour edition.
I just checked a facsimile editon of the black-and-white version, and there Snowy did indeed "latch onto" the back of the car!
In that version there's also a spare tyre on the back of the car.
I then checked a facsimile of the first colour edition and in the picture of the back of the car both the tyre and Snowy are missing.
Now it would be interesting to know if the mistake had already been made in the Tintin magazine version (I don't have a copy of that one).

JKM
I just checked, and the tyre on the back of the car and Snowy are still absent from the Tintin magazine version.

It is not impossible that Snowy managed to slip into the car and hide on the floor of the rear passenger seat. Even if the kidnappers had seen him, they would have been in too much of a hurry to bother to get rid of him.

JKM and CaptainFatstock
Nice observations of the other versions of this incident.

mct16
In both the Vingtème and the Tintin magazine versions, when Tintin's initial kidnappers are caught, there are shown to be three of them (including the driver).

So one of them had to have been sitting on the rear passenger seat; if Snowy had snuck into the rear passenger seat, he would surely be seen.

I don't think it probable that Snowy wouldn't want to stop them (or at least try to) and get thrown out of the car in the process.

This hurdle was initially managed in the Vingtième version by Snowy latching onto the back of the car while in the magazine version Snowy was completely ignored.

In the final album version however, one observes the presence of Snowy in the frame where the kidnappers are putting Tintin into their car, while being absent from the said frame in both the previous iterations of the story.

This shows that Snowy was not forgotten in the album version, at least signified by his fresh appearance in a scene where he was previously absent.

Since in the final version, there are no Zionists and Tintin's kidnappers don't get caught, we have to assume there were only two kidnappers (including the driver) unlike the previous iterations, and as you said, Snowy snuck into the rear passenger seat (most likely purposefully unnoticed).

So, the Snowy paradox is apparently removed with the exclusion of the Zionists from the scene.

That, or as jock123 said, a pair of Calculus patented rocket skates did the trick! ;-)