Rated 3 out of 5 stars

Wish this still worked! But for those of you SEARCHING for a way to add Google Contacts as a tab AND Google Calendar as a tab - I found a way. I added the following Addon Google Calendar Tab. Then opened that tab (Tools/Google Calendar - at bottom of menu). Once Google Calendar is opened and you are all logged in. Go to the GOOGLE black tool bar. Select Gmail. It will open a tab for Gmail. Verify you are logged into the correct gmail account that has your contact - duh LOL. THEN simply dropped down "Mail" upper left under "Gmail" and select Contacts. Viola. now ya got both of what you need in your Thunderbird. Use gContactSync and you can then send email as Thunderbirds contact list will sync with Google contact. Took me days to work this out! So I really hope it helps some one else.