Ok, still not sure they're even discussing the right commercial... a little further down in the same log I found "the REAL answer" about that commercial, and then several other answers about mercedes commercials
Built to Spill - Some Things Last a Long Time
Mozella - Amazed
could either of those be it?
Amazed was labelled "haunting", but Mozella is a singer/songwriter so it might sound folkish too, I'm not sure. On the other hand I didn't realize that these were both (or all 3 if you count my mis-found last one) were from the current ad campaign, and I don't believe the current ads have the scenes described. These ads had pictures of drivers and their Benz's. The "Pictures of You" was a mistake, should have been the title to the commercial perhaps, but not the song playing. I give up trying to find this answer unless I see this ad rerun some time so that I can look it up, I was just feeling crazy last night and ran some searches & came up with a bunch of sites talking about the ad, but the answers I found threw me off track apparently.
Hope this helps.