I didn't know about this thread else I would have posted this sooner, I recently had the same problem with a sim dropping her 'go to work' from queue, what worked for me was to make her a second career outfit with the stylist station, after that she left for work fine.
It seemed the game had lost her default career outfit, I could see it with the stylist station or dresser but under the change outfit menu it was gone until I created a second outfit, then it returned.
So try making a new career outfit with the dresser or stylist station then change them into it and they should get in the car pool.
This is one of my job challenge sims so I've had to rinse and repeat for each job, bit of a pain but at least it works for me.