When Leslie and Ben are driving to Indianapolis, you can see that they both have put seatbelts on their briefcases, which are sitting on the back seats.
The band that April likes, Neutral Milk Hotel, was an American band formed in Ruston, Louisiana, by musician Jeff Mangum. They were active from 1989 to 1998, and then, from 2013 to 2015. The band's music featured a deliberately low-quality sound, influenced by indie rock and psychedelic folk.
Jerry, Donna, Andy, and April play Tom's version of the Newlywed Game. In an episode of Brooklyn Nine-Nine (2013), Jim O'Heir plays a local sheriff who uses the Newlywed Game to interrogate suspects.