One on one time together is definitely harder once you have kids. My hubby and I hit the road this weekend with our 9yo and 2mo to go visit our 23yo. It was a long drive and our little one slept most of the way while the boy put on his headphones and played video games, read books and did puzzles. My husband and I talked about everything under the sun for the entire drive. It's the first time since the baby was born that we've had that much uninterrupted to talk and it was awesome. :-)
This is one of the reasons that my wife and I go road tripping several times a year. Our kids now are road warriors and do very well with this.