Mine can be a bit hit and miss at times too. I back my truck in so that may have something to do with it depending on where the antenna is. It seems to go in stages where it works fine for quite some period of time and then not so good for a period of time. When it hasn't been working I have looked at the DIC and it indicates that it is transmitting. :h
My wife's Acura MDX works the vast majority of the time but sometimes it doesn't either. We have keychain remotes that are programmed for our garage door and alarm system so it isn't a huge deal when they don't work, just an annoyance.
So I don't think issues with these is uncommon but it seems ours work most of the time. Please let us know how you make out.