'Journeyman' - "Winterland"
While Dan Vasser was interfering with the life of Abigail Armstrong back in the early 70s (either 1973 or '74), a VW bus pulled up to offer her a ride. And the music playing in that bus?
"Shambala" by Three Dog Night.
This was the song of choice on the cassette tape in the Dharma bus where the father of Ben Linus met his end on 'Lost'.
No way I'm going to stretch logic to the breaking point by trying to make the case that the bus on one show was the exact same one as on the other series.
However, there are a lot of coincidences that have occurred for different characters on 'Lost' which tie them together. It's a universal effect which doesn't just happen on the island but in their past lives all over the world. And being a universal phenomenon in the TV dimension means that this is the kind of thing that has an effect in other shows.
It could be that whoever is pulling the strings behind the curtain, in regards to Dan's mysterious ability to travel back in Time, they could be involved with the DHARMA initiative or the Hanso Organization. It might be the reason we see Walt keep popping up at strange moments on the island.
Or it's all just coincidence.
But even if it was coincidence, it's hard to top this moment right after that encounter along the coastal highway:
After hearing what had happened, Dan's partner-in-Time, Olivia Beale, said, "Well, I'm lost!"
I'd almost think they were going for one of those patented Extras in-jokes!