It's not unusual for those exercises to be super-hard when you start doing them. Do as many as you can, and realize you may only be able to half-*** some for a while.

That seems like a long test! It would take me forever!!! I lose track of time all the time... I lose HOURS... it's amazing.
I would test positive for a lot of those symptoms, but I don't have ADD, they're due to other issues that would exclude it.

I hope that the dealership gets your car back to you the day after you drop it off. Once there was a recall on my car and they had it for several days because they didn't have the part in stock when I dropped it off. The last time I made an appointment for a recall I made sure they had the part in stock before I dropped it off.