Was going to start a thread on this. I log on after a week or so to see that someone beat me to it.
I have keyless. Car is now nearly 17 months old. Message saying key not found started showing up. This week after footy on Tuesday message in display no key located I had to manually start it. Luckily I had read the manual a few weeks prior car started got home car didn't lock. Had to get the spare out to lock.
Straight in to the bay 4 Duracell cr2025 for 4 quid free postage.
I think keyless does use more battery I also read if you use the fob from further away it uses more too.
Either way new batteries will be here today so I will switch back to te old fob.