We took Amber on her first 6 hour car trip at 5 weeks old - she was an angel. Slept the whole way.

I took her on her first flight at 8 weeks old, once again absolute angel - slept the whole way.

She then had another 6 hour drive at 5 months and she was an angel for the first half of the trip and a horror for the second half, just had enough of sitting in the car seat.

I bought her new rattles before each trip so she had something new to look at, sat in the back with her for a bit and read her stories and kept her hydrated and she was happy.