Thank you @ellatrixb for your support. And I haven't been rude, I've acted very reasonably since being called crazy for considering it! There is so much conflicting information around, as this post shows, that none of what I've asked is unreasonable and I should never have been ridiculed or vilified for trying to come to a balanced, practical and safe solution for our family.
It would cost £9k to hand the car back early, and we need an electric to get my salary down, otherwise we'll pay an extra £10k a year in nursery fees. That is not an option!
Did any of you even read the link from @BertieBotts ? It all makes perfect, logical sense to to me. I'm very open to having my mind changed by statistics, facts and logic (this research has already done that, in that I will be keeping my eldest rear facing for a while longer still), but so far nobody has shown me any. Please do show me, if you can!
If the air bag is switched off and studies have shown it won't accidentally go off in an accident, then why exactly is the front unsafe? Even if you can't show me a study or a statistic on it (I've looked and found nothing), then explain logically please. In my head, it's as far from any potential point of impact as they would be in the rear and if anything the front dashboard and sides are more reinforced than the back is anyway, as that seat is more often occupied that the rear ones, so manufacturers invest in better protection.
So what exactly makes it unsafe? Nobody so far has been able to say why. And, if you can show me this, which then is safer for a 4yr old; forward facing in the.back, or rear facing in the front? As that would be the decision I'd need to make. And why?