The character played by Bill Nighy holds guns with just a thumb and middle finger, with his index on the trigger. This unusual grip is because he suffers from Dupuytren's contracture, which means he can't straighten the ring and little fingers on each hand.
(at around 1 min) During the car chase scene, Rose starts out driving and then during the chase she switches seats with Victor. The camera moves to the car chasing them and then cuts back to Tony sitting in the back. From behind you can clearly see Rose still driving.
When Victor is massaging Rose's feet, in the close ups you can tell that a hand double is used because all 5 fingers are straight however Bill Nighy has Dupuytren's contracture which means that the last two fingers on both hands are permanently pointing inwards. This is visible in the wide shots.