These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
It's actually implied that the person they nearly hit is with a large group of people who are going to the beach for baptism, which then leads to many enjoying their time at the beach. Dodge and Penny just ended up following them.
Everyone partying it up before the end of the world. Patton Oswalt's character reveling in the loose sex he's been having since the reports is the cherry on top.
The whole Friendsy's scene. Everyone looks like a bunch of ravers (and are even rolling on ecstasy or getting stoned) and just accepting anyone that's coming in.
The random guy in the police station, wearing a sandwich board proclaiming the end is nigh. Dodge calls him "a peaceful, validated man."
Dodge returning home after being on the road for about a week and finding his housekeeper Elsa still there, cleaning as if it's not the last day before the end of the world. Dodge's reaction: "Are you shitting me?!" Doubles as sort of a Heartwarming moment, since Elsa considers Dodge her friend and continues to work, whether or not she is aware of what's been going on.
The silent nod between Dodge and his father as he puts Penny on the plane.
Dodge comforting Penny at the end as the asteroid nears.
The first loud noise from the impact, and Penny's face when its heard.
"Elsa?! Why are you still here? GO HOME!"
That part is even worse when you understand that Elsa is pleading with him in Spanish because she considers Dodge her friend.
The TV anchor signing off and saying "God bless you all."
The ultimate Fridge Horror with each "Last..." thing shown is how everything in civilization is slowly stopping, being ground to a halt. No more publications, or music, or new things. All of the children/infants seen in the film? Their lives are over before even beginning. Many of them won't even be fully aware of what's happening.