To open or lock the 2007 saloon, I need to have the fob up close to the front windows, it will not work if I am at the booth. Tried both keys, checked the batteries and replaced them anyway. About two or three times a year, the alarm will go off outside my house, off road parking. 

Is the vehicle battery also in good condition?

Sounds silly but try holding the fob to your head and testing the range.....strangely enough it boosts the signal