Hanoi Airport Transfer ?
It takes about 2 hours from landing time to arrival to your hotel.
It can be booked in advance at booking@noibaitaxi.com or taxinoibai@yahoo.com and check the web for more info
http://www.noibaitaxi.com
You have 4 choices to transfer from airport to Hanoi central:
• Easy way is by taxi (VND 250,000 or about $16): please be very quick to call a taxi once you finished passport control procedures & get your luggage if your flight arrived so late. Some bad taxi driver may tell that "Your hotel is full tonight" then take you to other bad hotel to get commission, so please ask the driver take you to exactly address of your hotel.
• Cheap way is by 15-seat mini bus of Vietnam Airlines ($2/person) to Vietnam Airlines Head Office at No. 1 Quang Trung Street, then walk to your hotel.
• Cheapest way is by public bus (no luggage & before 21:00 only): first you get bus No. 7 (yellow & red color) VND 5,000 from Noi Bai airport to Cau Giay, then change into bus No. 9 (VND 3,000) from Cau Giay to Bo Ho (Hoan Kiem lake in Hanoi central), then walk to your hotel. The total costs for both bus trips would be VND 8,000 (or 50 US cents).
• Some hotel offer free airport pickup service if you stay more than three night. In fact, they included pickup charge to your room charge.