Has anyone booked direct with Tristar ?

Flew from BOM-LHR on a full J ticket for once (it was one way) and was very impressed by the car (S-class Mercedes) and chauffer. Massive boot for our 3 large bags and various smaller hand luggage after experiencing the joys of shopping in India.
I see on another thread that VS uses Tristar for their limo service. Been to their web-site and can only get hold of a phone number for their sales team. Being a Saturday, no one was there. I only wanted to get a quote for a trip to LHR next week for comparative purposes (not fussed about the no Drive Thru check in) as I am on a Z ticket from the current UCS sale.
Has anyone here tried to make a personal booking with Tristar or do they only do contract/corporate work? Their web-site allows you to make on-line bookings but only if you have an account with them first.
I see on another thread that VS uses Tristar for their limo service. Been to their web-site and can only get hold of a phone number for their sales team. Being a Saturday, no one was there. I only wanted to get a quote for a trip to LHR next week for comparative purposes (not fussed about the no Drive Thru check in) as I am on a Z ticket from the current UCS sale.
Has anyone here tried to make a personal booking with Tristar or do they only do contract/corporate work? Their web-site allows you to make on-line bookings but only if you have an account with them first.