Depends on where you're at in your labour.

With DS1 I drove myself to the hospital and back again (I was 1-2cm dilated both trips - and DH had been drinking, not much but enough that I didn't want to risk him driving). However on the return journey to hospital several hours later (think I was about 7cm dilated) there was no way in hell I could sit, so kneeled facing into the front passenger seat with my arms wrapped around the seat. Thank God it was 2am!! DH wasn't too impressed but I remember telling him to bugger off when he wanted me to wear the seatbelt. You can't hug a car seat properly with a seat belt around you. LOL.

With DS2 I was mentally more prepared and while I was well and truly in the throes of labour, I was able to sit out the 20 minute trip. Definitely wasn't the most comforable of trips, but I just tried to relax as much as possible through the contractions and told DH to "hurry up!!!!!!!".