Diono Monterey 2 review

Our rating 
4.5 out of 5 star rating 4.5

In a nutshell

High back booster seat that expands upwards and outwards, with extra deep metal reinforced wings for side impact protection.
Ease of installing
4.0 out of 5 rating 4.0
5.0 out of 5 rating 5.0
Safety features
5.0 out of 5 rating 5.0
5.0 out of 5 rating 5.0
4.0 out of 5 rating 4.0
Worth the money
4.0 out of 5 rating 4.0
Pros: Provides deep padded protection, easy to adjust width and height.
Cons: All that padding means a wide seat, which may partially cover the car’s seatbelt clip.

The Diono Monterey 2 is an updated and improved version of the popular Monterey (originally known as Sunshine Kids Monterey). It’s a group 2/3 car seat designed to fit a growing child from 4-12 years old which easily changes size to match your child’s growth spurts.


Not only is the headrest able to adjust to 11 different positions – changing by up to 16.5cm in height – the width of the seat can also be expanded by up to 50cm simply by turning a dial on the rear of the backrest.

It is the only booster seat to have extra deep metal reinforced wings for side impact protection and a structured seat base for strength. This increases the protection for your child if there is an accident. 

What’s in the box?

  • Monterey 2 car seat
  • Instructions
  • Cup holders

Is it easy to install?

Yes – if you read the instructions (more on this later)! The seat comes in two parts: a stand-alone booster and attachable high back to support your child’s upper body. Both parts simply click into place by sliding the booster into the backrest. It can be anchored with ISOfast connectors, which click into your ISOfix anchors if your car has ISOfix, or via a seatbelt, which is how we use it with my 4-year-old son Jack.

A big thumbs-up to Diono’s instruction manual, which is very well written and is a breeze to follow, but make sure you read the instructions first. I gaily ignored this fundamental step and spent a good 20 minutes in the car, on the doorstep and finally away from public view in the lounge trying to link the two parts together. Eventually I gave in and consulted the instructions to find I had to lay them completely flat in order for the backrest to ‘click’ into the booster. 

The seatbelt guide was useful to find the safest position for the belt to sit but I found in our car (a standard Ford Focus) the seat does partially cover the car seatbelt clip, due to its width. However, this hasn’t proved to be much of a problem for Jack.

What about Monterey 2’s safety features?

For a group 2/3 car seat, there are a reassuring number of safety features. The extra deep reinforced metal wings provide significant side impact protection and that the seat is contoured to help keep Jack sitting in the right position. If you have ISOfix, you can use the Monterey’s ISOfast connectors to give additional attachment to the car.  The Monterey 2 was recently awarded the top score in the group 2/3 ADAC testing in Germany.

How comfortable is it?

Jack was keen to comment on how comfortable the car seat is (like sitting on a fluffy cloud apparently), especially on long journeys. This may be down to its super thick AirTek™ foam, which is designed to increase airflow. Its two recline positions also allow the Monterey 2 to adapt to fit all vehicle seat shapes and when Jack fell asleep on a recent long journey, he didn’t look to be in any discomfort as the headrest kept him snug enough to stop his head from drooping forward. I’m in little doubt the Monterey 2 will see Jack through until he reaches the grand old age of 11.

Any other highlights?

Unsurprisingly, Jack was most excited about the retractable, extra-deep dual cup holders, which are angled to keep drinks upright and are on either side of the seat so Jack can easily get to his drink no matter what side of the car the booster is situated.

Is it easy to clean?

I had one gripe, and that was down to both the maunal and instructions stating that the seat cover was hand wash only.  As most parents are only too well aware, long journeys can often result in an unwelcome visit by the vomit fairy and if you can’t get to the stain quick enough, no amount of hand washing will get rid of the smell. 

However, after checking with the manufacturers, Diono confirmed that the cover is indeed machine washable on a 30-degree wool, hand wash or gentle cycle – not a hot wash.   

What are the optional extras for the Monterey 2?

  • GripIt (A full seat surface protector mat) – £24.99
  • My Stuff (Storage pocket for your child) – £5.99
  • Stuff’n Scuff (Vehicle back seat protector) -£13.50
  • Travel Bag (Waterproof backpack or in-hand bag for transporting the carseat) – £17.20

Are the optional extras needed?

I found the GripIt car seat mat really useful as it stops the booster seat from slipping, protects the upholstery and is also ISOfix compatible. But I was less than enamoured with the Stuff’n’Scuff back seat protector. I can see the logic behind the pop-open waterproof fabric protector as both my children have a habit of kicking the back of the front seats with muddy shoes. However, I found it hard to fix it to the bottom of the driver’s seat as there was nothing to tie it to, whereas the top fixes to the headrest easily. However, I did find the top pocket very useful for storing Jack’s toys and colouring books.

MadeForMums verdict


The Monterey 2 is a fantastically safe and practical car booster seat. It feels sturdy, is comfortable, has excellent side impact protection and expands as your child grows, giving a snug, safe fit from pre-school to the end of primary school.