That is good advice and all I find I have to do with my '10 XKR but there isn't a continuous drain if you don't lock it, it just take longer for everything to shutdown which may ultimately run the battery down to the point where you start getting all sorts of weird electrical glitches from modules that don't boot up properly or in the right sequence.

 

Welcome to the Forum. I see that you just joined and your signature shows that you have a 2007 XJ8 VDP.

This is the X150 Forum, for 2007 - 2015 XK/XKR models. Your 2007 XJ is an X358, and that Forum is here: 2003 - 2009 XJ Forum (X350 & X358)

I noted that the post you replied to is almost 9 years old, and I suspect that was a mistake. If you posted your comment after having scrolled down to the bottom of the page, you became a victim of the Forum's Infinite Scroll feature, which takes you to older, related threads.