I use this when race ends


And i want same style event when qualification ends.

You need this event to do that:

OnFinish : trigered when a player finish a race or qualification

If i use OnFinish my qualifications stops when first car get first time and this didn't activate my countdown sub.

And you want the countdown to start when the last player finished qualification?
Then you might have to do something with a delayed command that gets started when qualify start.
Let us say that qualify is 10 minutes, so at the start of the qualify you run a delayed command that does something after those 10 minutes.
This might be useful for what you want:

HostDelayedCommand - Set a delayed command on the host rather than a player

Delayed commands are set by seconds, so you could set it at 10 x 60 = 600 seconds and then take into account that a player can finish his lap when qualify time runs out. So maybe at 2 minutes to that delayed account.

I have not really tried the above suggestion, just doing this mostly from memory.

If i use delayed command i need event when last driver qualified because when trackrotation start ...

No, the delayed command will run when the timer expires, whether the last player finished his lap or not. That's why I said that you need to set the timer to the duration of the qualification and add a couple of minutes to take that very last lap into account (within a reasonable time). You will know the world record for the track+car(s) (take the slowest car when you have multiple ones) and then add like 10% (of course this is just an example and you need to work out those numbers to your situation).