Carla said "wonderful" because Lenny looked exactly like Brent Foster and was the perfect stunt double. Lenny meant that the person shooting at them in the Mercedes was not part of the movie scene they were meant to be filming. Lenny turned the car around and drove the Mustang straight at the Mercedes. The Galata Bridge was opening. Lenny just found out that the red light and siren he thought earlier was the police investigating the car chase was a warning to drivers that the bridge was about to open.