3 year old in front seat...

[helsi]

I was coming out of the supermarket today when I saw a mother putting her child of about 2.5/3 years old in her car seat in the passenger seat of the car.
I stood and watched and she did seem to fasten her in securely. It was one of those seats that uses the general seat belt to fasten in with.
Is it illegal to put a child of that age in the front seat?

I will try not to start on my rant about car dealers, but with dd aged four, I went car shopping and all garages said about putting her in the front with an active airbag while she uses a high backed booster (we also said that we wanted to take two other children/babies who could be in rear facing because of when we take her friends out and we are ttc). Also, one manufacturers helpline suggested putting the highbacked booster in the middle seat in the back, when the car only had a lap belt there and the car seat manufacturers instructions specially said that it must use a three point belt.

We were looking at cars up to a couple of years old and nearly all could not have the passenger airbag deactivated. The advice I could find regarding side airbags was that the children - front and rear - should not go to sleep with their head on the door. In my old car - which did not have any airbags - dd was nearly always in the front, because it was a three door and I could not easily strap her in properly in the back (as I could not reach her fully) in addition as a new born we could not find any that fitted in the back and we could not afford at all to change the car at that time. Also, all the accidents that anyone my family has been involved in have been rear or driver's side - I know statistically that is unusual - but it meant I felt more comfortable with her on the passenger's side.

We have three highbacked boosters, so we can give her friends a lift and she has one if she goes in anyone elses car although I know a lot of her friends at school only use the booster seat part know and they do fit a high backed booster - as they use that in my car.

I also have a question that I have not been able to find the answer to, what about on school trips should children be allowed to take car seats to use on coaches or do the coaches only have lap belts?