2011 ford fiesta with ford sync and iphone 4 ios 7

i just got a 2011 Ford Fiesta with Ford SYNC. I have my phone in sync via bluetooth, and I am able to place calls, view recent calls, scroll my phonebook, answer calls, play music, etc. What I cannot seem to do is read text! I hit the text button just to try it out, and it told me the feature was unavailable. I did a quick google search and saw various posts about this problem, but they were all quite old, and the users had iOS 4 .. i have iOS 7.0.4 (i cannot update to anything newer because I have the 8GB and no matter how much i delete stuff the memory doesn't free up for the update??) Is the texting feature with Ford SYNC still unavailable to iphone users or what????