Kevin and his girlfriend jump into her car (a mid-sized silver/tan Grand Prix with a removable t-top and/or vinyl roof). The brother and sister-in-law jump into another vehicle (a big, black, jacked-up Ford pickup). They figure something must be going down at the Del-Win Ballroom, so they head in that direction.
For reference, this is a gold 1985 Grand Prix with T-top
Once they get to the Del-Win, they can’t see any squad cars… no lights… nothing. It’s like they’ve all just disappeared. They take a back road that goes behind the Del-Win and come out to 16th Avenue/91st Avenue (the road where Jacob was abducted). At that point, the brother decides to head home because he has to work in the morning, so he and his wife turn right (north) and head back toward town.
http://www.joybaker.com/2013/03/14/kevins-story/
Since we are nailing on DR too much again, I"m going to share another theory. Kevins girlfriend owned a gold grand prix with a vinyl roof. DR says he saw something like a tan monte carlo whip that u turn in his driveway, well maybe he was a bit off. Maybe this is her in the afternoon by herself or with kevin? They come back later in kevins small dark car and park in "lovers lane" when they are interrupted by the boys flashlights. Kevin is angry, gets disguised and waits for their return. They abduct Jacob and turn around in the building site, DR saw this. Then once they get the word on the scanner, they scurry back in the gold grand prix again to cover up kevins small dark cars tracks and possibly remove the bikes.