You can book a taxi via following methods:
Online: http://www.tri-cars.com/
Telephone: +44 179 887 5779
Email: info@tri-cars.com
Yes, it's possible to pre-book a taxi with Tri-cars Taxis Booking Office, please contact the company.
Tri-cars Taxis Booking Office has both regular and air-conditioned taxis, please mention your preference at the time of booking.
Please contact the company on their helpline number to make any changes.
Generally drivers will meet the passengers at the arrivals on airport pick ups but do check with the company.