You have experience (19 reviews), so I don't see the problem to be as big as you think.
1. Set up appt ahead of time. TELL HER ABOUT THE SITUATION TO PREPARE HER FOR #5.
2. After your business, call from your room to make sure that all is well and on schedule.
3. She will tell you her location at that time (hotel or which of a few hotels all in the same area).
4. Catch a cab to that location.
5. While in the cab, call and ask for FINAL details using language the cabbie won't suspect:
- Hi, it's me. I'm almost there.
(Code for "Hi, it's me. I'm almost there.")
- Were you able to get tickets? Reserved seats? What row?
(Code for "What floor and room number?")
- Sounds great. I'll meet up with you soon.
(Code for, "Sounds great. I'll meet up with you soon.")
And so on.
If she is hosting from a residential neighborhood, change the lingo to get close and then,
5. In the cab,
- Hi, it's me. I'm almost there.
- Yeah, I'm early, but I thought we'd go over the notes for tomorrow's presentation.
(Code for, "What's the address or apartment number. Don't worry, you're not on speaker so the driver can't hear you.")
- Well, if you don't mind taking your car, I'll just tell the cabbie to leave when he drops me off.
(Code for, "Since I'll be hanging with you for a while, I'll just tell the cabbie to leave when he drops me off.")
And so on. Of course, it's easier for me to suggest all of this because I'm not in your shoes surrounded by co-workers I'm looking to ditch for extracurriculars come the evening.
Good luck.
Posted By: indydriver
Going on a biz trip at the end of the month and hope to line up a date with one of the local ladies. Thing is I will not have access to transportation. The resort takes care of getting to and from the airport then the company busses everyone to where they need to go during the day. We have the evenings to do what we want but there is no real reason to rent a car. I totally get the reason for the 2 call system so please don't get the wrong idea here. Just thinking it would seem kind of weird or look suspicious to tall a cab driver to take you to such n such location. Then wait while you make a call and then tell them to take you here. Another thing for the ladies is what about the customer hanging around outside for a cab to show after the session. There are some outcall options where I an going but some of the ladies I realy want to see only offer incall. Any suggestions?
...anyway; he's paid to drive. It's no big deal if you stop at one place and continue on to your destination. If you tip him, he won't care if you stand on your head while in his cab. Chances are, if he has a dick he knows what you're doing and has driven others in your shoes before.
And when you're finished, call a cab while you're chatting and getting dressed. It should be there by the time you get outside.
Please keep in mind that even though you may be used to the procedure you described, not all ladies do things that way. Also, a "2 call system" does not necessarily mean exactly that. Even if it's in her reviews, that might not be accurate, either. 
Reviewers have stated that I have a 2-call system when in fact, I don't even do phone calls. Confirmation & arrival are handled only by text message with me. Guys will sometimes text me when they're close to my location, but since that's not what I instruct them to do I respond, "Great! I'm ready & waiting so please text me back for my room number when you arrive!"
For me, it's important to give that information out ONLY when I know he is on his way up to me. But that's me and I can be kinda weird about some of this stuff. LOL. 
xoxoxoxooxoxoxoxooxoxoxoxoxoxoxoxxoxoxooxoxoxox
