What Car has featured Multimac again this year, and that’s worth pausing on. Getting mentioned once by a major motoring title is a nice moment. Getting mentioned again, in an updated guide a year later, is something closer to a pattern. It suggests that when What Car’s editors sit down to work out what genuinely solves the “how do I fit three or four kids in one car” problem, Multimac keeps coming up as the answer.
The 2026 update to What Car’s best car seats guide, written by consumer editor Claire Evans with testing support from Child Seat Safety, covers 26 child car seats across five categories from infant carriers through to high-back boosters. Buried in among all that single-seat testing is a section that isn’t really about a single seat at all: “How to fit three or four child seats in a car.” That’s Multimac’s section, and it exists because none of the 26 seats above it can solve that particular problem on their own.
The core facts will be familiar to anyone who read last year’s coverage. What Car runs through the seven available sizes, the fact that the system anchors into the car itself rather than relying on Isofix, and the range it covers, from a Mini to a Rolls-Royce. They note the four-seat Multimac starts at £2,299, working out at under £4 a month per child if you use it from birth to age twelve. The Minimac infant carrier gets its own mention too, at 9kg and £499, with its head-hugger support and dual foam inserts for newborns and older babies.
What’s genuinely new is that What Car actually fitted one. They put a four-seat Multimac into a Tesla Model 3 and tested it with baby and toddler dummies. Given how narrow the seats look compared with a row of individual child seats, that’s not a given, and it’s the kind of scepticism you’d expect from people who test 26 seats a year. Their conclusion: the seats proved “roomy enough for both children, with good support.”
That’s not marketing copy. That’s an independent testing team who could easily have found the opposite and said so.
It’s worth asking why Multimac keeps earning a spot in coverage that’s otherwise about single seats. The honest answer is that the problem it solves doesn’t have another solution. A family with three or four children either upsizes to a seven-seater, crams narrow single seats across a standard bench and hopes everyone still fits as they grow, or looks at something like Multimac that’s built around the actual problem from the start. What Car’s testers, who spend their working lives assessing single-child seats, clearly recognise that Multimac sits in a different category entirely rather than competing with the seats they’re rating above it.
The R129 accreditation gets a mention too, which matters more than it might sound. That’s the same safety standard against which the individual seats in the guide are being judged, and it puts a bench-style system that seats multiple children in the same testing bracket as the latest single-child seats on the market.
If you’ve got three or more children and you’re currently doing the maths on a seven-seat SUV versus keeping the car you’ve already got, coverage like this is useful precisely because it isn’t coming from Multimac. It’s an independent motoring title, with its own testing standards and its own reputation to protect, looking at the same problem you’re looking at and reaching the same conclusion.
If you want to see how a Multimac would fit your car and what it would cost, the quote builder will work out the right size for your vehicle and give you a proper price based on how many children you need to seat.
We’ll keep flagging coverage like this as it comes in. When the people whose job is testing child seats keep landing on the same answer for multi-child families, that’s worth knowing about.
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