Hello I'm a new member here I own a 2005 XF convertible... owned the car for six years but I'm having trouble with keep rear tires on it... Since I owned the car the rear tires would last about six months and shoot any idea

 

You need to see a foot specialist. I had the same problem. After several visits, I was able to reframe from stomping my right foot down so hard I would literally mash the accelerator all the way to floor. Once I broke this habit my rear tires have lasted a lot longer......

 

Ha-Ha! Great 1st post and WELCOME to the forum.

 

Before you pay the doc, (podiatrist) be sure you don't have a cheap Dr. Scholl's Chinese made leaded insole in your shoe like I did. Otherwise, yeah, you might have that "sudden ankle reflex syndrome". A lot of motorcyclists (with straight pipes), have the same condition in their right wrists! Especially at stop lights!

 

Are the tires wearing even across, or down to the cords on the insides ?
If the latter, then the toe in is probably way off.
Camber could be wrong too.

( Go get a laser alignment check, report back )