Theres “in car safety centre” in Rayleigh. They’ll have a full range of car seats, they’re also experts in car safety unlike smyths etc.. who only have basic training. They have a website you can look at aswell x
Halfords have a section
Car seat ninja in bishops stortford, they will even fit it correctly x
John Lewis! Very helpful and will ensure to demonstrate how to fix the base to the car and then the seat on top
I will be going to Little Bubba’s Baby Shop in Ipswich. A long way to go but they are very knowledgeable and support extended rear facing which is really important to me as it is 5 times safer. Also they sell Swedish tested seats which are much safer than those which only comply with the bare minimum standards.
John Lewis or boots!