Dialing Work Extension

I am using Bluetooth to connect my LG Thrive to the Prius.

I set up a contact to call a work number. I need to dial an extension after the system answers the phone. In the contact manager, I entered the telephone number, pressed the "Wait" button, then entered the extension number. The number looks like "5551234567w8054".

When I dial the number (i.e. select phone, select contacts, select the contact name, select the number, and press the dial icon), the system dials the 10-digit telephone number correctly. When the system answers the phone, I press the "0-9" button, which opens the send tones screen, with "w8054" at the top and the number pad greyed out. I press the "Send" button. It sends tones and I get connected to the wrong extension. It appears that the Prius Bluetooth system is properly waiting when it sees the "w" in the telephone number, then sends the "w" along with the following digits. Of course, since the "w" is really the digit 9, this is received as extension "98054" instead of the extension "8054". (This is just my guess - I can't really tell what it is sending at this point.)

I can't find any documentation on what the LG Thrive does with the "w", nor can I find any documentation on what the "Wait" button does in the Prius contact manager.

Does anyone know how to enter a telephone number and get the Prius Bluetooth dialer to stop after the 10-digit telephone number, wait for my input, then send the 4-digit extension number (without sending a superfluous "w" character)?

I can't enter the contact into my LG Thrive and download it to the Prius. I have not been able to download ANY contacts from the phone to the Prius. (I don't really care, since I only have a couple of numbers which I would dial from the car anyhow.) I entered my contacts manually using the Prius Contact Manager.