OK so here is some feedback from me.
It was not specified how much time we had until start of the race. Qualification ended, then for a long time nothing happened, then suddenly 3 seconds countdown appeared, which resulted into many people staying in pits and losing their qualificiation position. This resulted into few people leaving right after race started. You should have given more than 3 seconds and at least some warning for drivers. Not everyone participates in events regularly and people also use to forget to leave pits in order to keep their quali position.
Second.. I saw many drivers of [GU] team while I was training on your server, but in the end, only one or two participated. If you would do these events regularly, you should easily reach good amount of drivers participating. Looking at 9397 events that were very similar to this, it started with races of 5-6 racers and in the end, there we almost 40 drivers qualifying and more than 20 racing.