Dean, try this website:
Wait for the video to load, and watch "Lost Untangled".
It is hilarious, and will give you a synopsis of the episode (check it every week)
I can try to answer your question though; there was no real explanation how Daniel came back to the island in 1977, although we now know why he came in 2004 (sent by Widmore, who we find out is his father!)
As for the rest fo the Losties stealing a jeep to escape, it was because the Dharma security people, in particular Radzinski, who discovered that Sawyer (Lafleur) had beaten and gagged Phil (security) and hidden him in their closet. The jig is up for Sawyer and Juliet.
Fortunately, Daniel was able to convince Jack and Kate they needed to GET OUT NOW, but first he needed to find his mother, Eloise. That's when the shootout started, as they were stealing the jeep to go into Hostile territory to find Eloise.
Didn't you just LOVE the line when Sawyer said to Daniel, "Your Mother is an Other?"!!!
CAn't wait till next week!