If a 14 month old will kick their legs such that the rear facing car seat will move... what will it be like with a 3 year old in it! Certainly some car seats can be fixed very securely to the car, but many are held in by a seatbelt. The seatbelt is designed to move, so if the child pushes against the back of the adult seat with their legs, the car seat will move.
I therefore consider it to be impractical given the current types of car seat in everyday use and in the current design of cars. With cars with ISOFIX and ISOFIX seats it may be more practical - but many cars do not have ISOFIX, even when they do have ISOFIX it isn't available at every seat position.
How many years until every new car has ISOFIX in every seat position (excluding the drivers seat)?
How many years until everyone can afford to buy a new car?
The 4-point ISOFIX system (which was in the draft standard) showed the best results according to ROSPA/Britax Source but due to the high cost, in 1995 the 2-point ISOFIX system was chosen.
The ISOFIX standardisation project started in 1990. It's been around a while and there has been some uptake of it. However I feel it will be some time yet before all cars driven in the UK have ISOFIX and all carseats sold are ISOFIX.
This is Not New News... there is a press release dated June 2008 about this subject Source: ANEC
Looking at the ROSPA Conference notes, plus the PRNEWSWIRE release, both are connected with Britax.
Yes it is good that this sort of thing is being discussed. Not so good that it only appears to be one manufacturer... why is Which and Britax providing this information and not the Governement test labs in Crowthorne?