Being that nobody has come up with a concrete answer for you, here's a possibility. In an old 2000 Radio Shack Police Call Directory I have, there's a listing for A1 Taxi & Limousine in Fort Lee, New Jersey - 452.500. I checked the FCC Database and there is no current listing for them and when I did a second search on the frequency, there was no license for them for it. You didn't indicate a location for them, but if this is, in fact, the company you are looking for, they could still be using the frequency without a license. Illegal, yes, but it happens. Another possibility is that they may be using Nextel.