We used to get this sort of "off on holidays" attitude (which in part I occasionally understood because for the office staff the only time they ever get in a plane is when going on holiday) UNTIL about a year or two ago, when myself and other sales team members fixed it once and for all (think I have written about this on FT before).
We had a little initiative where people from various departments of our IT company spent a day with other departments, a programmer did a day with a consultant, etc. So myself and our sales manager arranged for the principal protagonist, from the admin team, who is indeed our booker of travel, liaison with the travel agent, etc (in between the caustic comments) to spend a day with us, a nice easy day in the office with a 10.00 start for a presentation.
And then with 3 days to go we somehow switched the location due to "client request"

from London to Northern Ireland. So 0650 out of Heathrow for us all, with an "extra" half an hour early report because she had not done e-tickets as ever, and the BMI ticket desk has a huge queue at that time. So yes, you can get up in the middle of the night to stand in the queue as well. Not even seated together in the plane. We got to Belfast and picked up the rental car which she had booked as ever by default as the smallest, a Toyota Yaris, so we squeezed her into the back and did 2 hours down the road to Londonderry in it while taking calls on our mobiles incessantly. And then we did an all day presentation, drove back to Belfast, "somehow" managed to miss the last plane back to London (

and we had no overnight kit), said the nearby hotel was too expensive for the expenditure reports she had recently produced so needed to taxi to another, were too late for any dinner, had deliberately transferred onto the early 0650 back from Belfast the next morning so another crack-of-dawn start, and were back in the office because we "wanted to make an 0900 meeting the next morning".
All throughout the day we were cheerful, positive, etc, to make the point !
Oh, and she was unused to completing expense reports as opposed to just filing them, so I just had to reject it on the last submission day as miscalculated and she had to wait an extra month for her reimbursement.
There hasn't been another word since, and a complete change for the better. And we are always asked now what is the most suitable size of car. I recommend the approach. By the way, we were never suspected !