Hartwen Back Seat Extender — Hard Bottom, Water-Resistant

Why you’ll like it

• It turns the back seat into one flat surface, so a big dog can lie down properly instead of bracing against a slope for the whole journey.
• A hard bottom panel bridges the footwell, rather than sagging into it the way a hammock does.
• The footwell gap disappears — which is where dogs slide down to, and where they stay stuck until you pull over.
• Water-resistant and wipeable, for the walk that went through a puddle and the journey home afterwards.
• It folds flat and lives in the boot when you need your back seat back for people.

Product information

What it is like to live with

The first thing you notice is that your dog stops shifting. On a normal back seat they are working the whole way: front paws braced, back end sliding, standing up again at every junction. On a flat surface they lie down within the first few minutes and mostly stay there.

The second thing is quieter. You stop checking the mirror every thirty seconds, because nothing is happening back there worth checking.

Fitting takes about five minutes the first time and under a minute after that. It folds down to roughly the size of a large laptop bag, so it lives in the boot rather than taking over your car.

Who it is for

This is for owners of medium and large dogs — the ones who will not fit in a car seat and never will. Labradors, collies, spaniels, larger crossbreeds. It also works well for two smaller dogs who travel together and would otherwise spend the journey negotiating for the same spot.

It is also for anyone with a new car and a genuine reluctance to see claws meet upholstery. The seat and door panels are the part people mention afterwards.

An honest note about safety

This is a travel surface, not a certified restraint. It gives your dog somewhere stable to lie and stops them dropping into the footwell. It has not been crash tested, and we make no claim about what happens in a collision. We recommend using it with a properly fitted harness and a tether.

Care instructions

• Wipe down with a damp cloth and mild soap. Do not machine wash.
• Shake out loose hair and grit before folding it away.
• Air dry fully before storing. Folding it damp is how covers start to smell.
• Do not bleach, and do not tumble dry.
• Check the straps and buckles every few weeks and tighten anything that has loosened.

Frequently asked questions

How much weight does it hold?
We are not going to quote you a number, because our supplier’s own materials give three different figures and we have not tested it ourselves. What we can tell you is what it is built from: foam either side of rigid load-bearing plates, not fabric stretched between two straps. It is made for one large dog or two medium ones. If you need a certified load rating, we are not the right shop.

Will the colour look exactly like the photographs?
It is black, but the exact shade and sheen can differ slightly between batches, and screens vary. The difference is small.

Will it fit my car?
It suits most cars, SUVs and pickups with a conventional back seat and headrests. Measure the width of your back seat against the 132 cm expanded size if you drive something small or unusually shaped.

Can passengers still sit in the back?
Not while it is fully expanded. It folds back in under a minute, which is the point of the design.

Does my dog still need a harness?
Yes. This gives them a stable surface; it does not hold them in place. Use a harness and a tether together with it.

Support and secure payment

There is a real person at support@hartwen.com who answers within a day on weekdays, before you buy as well as after. If you are unsure whether it fits your car, send us the make and model and we will tell you honestly.

Payments are handled through an encrypted checkout. We never see or store your card details. Delivery is free across the UK and takes 6–11 business days, and you have 30 days to return anything that is not right, with no restocking fee.