Refitting

Do you have enough staff in the Facilities/Offices/support staff page?

yes - it sets how many staff you can have altogether.

Do you have two cars, or is it just the one?

So if you have 80 staff is that the amount of people you have employed altogether - ie do you have people working in design and commercial as well?
The total should not add up to more than 80.

If that is the case then I have no idea what is going wrong.
Other than you hopefully did 'save' all the changes to staff you made

Good to hear that it is working ok now.
But I'm sure it will be logged and the devs will be aware of it if it happens again - or to someone else.

I was having problem similar to this a couple of days ago as well. Although im only 90% sure I refitted everything but the motor and only a few were actually refitted.

We had some fairly significant problems with the server on Friday.  Was it Friday you noticed these problems?  If so, it's quite likely your refit operation happened in the middle of the disruption and so didn't complete properly.  Sorry about that.  Please make another post if you notice it happening again though.