"Full lobby start" optional feature

[Akamataa]

I think is good idea to put "Full lobby start" optional feature in race lobby, sometimes i make race like "no limit" and then minimize game while i waitning for players. If  there would be option like that, I wouldn't have to check if anybody join and then If the race starts player will hear the engine sound (or music) so then he will know he have to alt+tab. 
It's also good to put simple sound signal when someone joins or leaves lobby... and another one for full lobby.