The Rock County sheriff's office originally had said the vehicle suspected of hitting the motorcycles on Highway 14 Sunday night was a Nissan. Later, authorities connected a fog lamp assembly recovered at the scene to an Infiniti QX4.
The Janesville Gazette reports investigators now believe the vehicle is a larger Infiniti, the QX56.
Sheriff's Capt. Brian Christiansen says another piece of debris was found to have a number on it. The dealership traced that piece, finding that it was specific to the larger Infiniti, model years 2004-07.
Killed in the crash were 24-year-old Mitchell Vance and 18-year-old Devin Julius, who grew up in Freedom. Three other motorcyclists and another vehicle avoided the crash.