Recently, my youngest daughter (18 months old) has been...reluctant to go into her car seat. Getting her in and belted required some ingenuity and a strong hand, as she squirmed and tried to slither her way out, with much wailing in the process. Her sister (three and a half) would often roam around the inside of the car instead of dropping into her car seat as well. Overall, starting a car trip was quite an ordeal.
Then, last Wednesday, A Mercedes-Benz station wagon plowed nearly full speed into the back of our car while it was stopped at a traffic light. The two girls were in the back, and my wife at the driver's seat. All the safety systems did what they should -- the back of the car crumpled strategically, and the car seats, seat belts, and airbags kept everyone restrained. The car was a write-off, however. (We get a new one this week sometime.)
The girls go into their car seats without complaint now.