I was very fortunate to travel to the Ring last year AND ride in a Taxi with Sabine. My wife and I had THE bestest time, even when travelling sideways!
I was planning our trip back there again in April this year, so I rang (from Australia) the Ring Taxi guys and they said they had no schedule for their rides at this stage (late January) for this season. They also noted that Sabine was NOT driving for them any longer, you can however do a ride in her little GT3
http://speedbee.de/10-1-home.html.
I emailed her (she actually replied personally to my email

) to see if it was possible to do a lap in the GT3, unfortunately not when we were planning to be at the Ring.
We have instead booked a RSR right hand drive Renault and will have 6 laps of fun for ourselves.
Sad times indeed, the Taxi was so much fun, the kiss and hug from Sabine post the ride was pretty yum too! We will make a point to go to her guesthouse for a meal, maybe she will be pulling beers when we are there.