The suggestion is for a counter next to or below the blue button, informing the user on how many Ads have been watched to earn the reward, out of the total allowed. Perhaps if possible the time remaining until ads rest.
The idea stems from often forgetting how many ads I have watched out of 8. Which kind of feels as if I am not training the drivers in the most optimal way. Doing the math, the 8 ads plus the 4 hours, there's about 60% of free regen time, that may not be used wisely.
On the other hand, I don't why it is not yet a thing yet in the game, which has me thinking that maybe it could have negative adverse effects on gameplay and fair play. Maybe some clever managers we're using bots or some form of automation the watch the ads for them... Yeah I know, unlikely but would be great to have an idea of how it could go wrong? Maybe it was tried before.
SIDE NOTE: I would not mind watching more ads if it would help the dev team in any way possible. As a fan of the game, who is may not be able to buy items on the regular, seems like watching ads is the least I could invest in terms of time and instead of money. If it results in aiding the game dev's raiser funds and capital to hire more talent to purchase more resources.