Every year millions of Brits take to the roads with a car full of camping gear and an eye on the skys. Despite our changeable weather, The Great Britain Tourism Survey tells us that we spend over six million nights under canvas every year and the value of camping to the British economy can be measure in the hundreds of millions of pounds.For full disclosure, I’m not included in those numbers. When it comes to a night away, room service and an en suite are pre-requisites for any travelling I do. But there’s always been something nagging away in my mind, a kind of what if…One thing that has caught my eye in recent years is the number of cars I see over the summer months with a TentBox on top – apparently there are now over 100,000 so-called TentBoxers, so that explains things. These clever contraptions promise simple ‘pop up’ camping on top of your car – no fuss with poles and ropes in wind and rain, it seems that you just turn up, open up and hey presto, a bed for the night.Sleeping six feet up on top of a car felt surprisingly stable, while the view was better (Steve Fowler)What really got me excited, though, was doing that with an EV, and my Hyundai Ioniq 9 seemed to be the perfect car, especially with what’s called V2L functionality. V2L stands for Vehicle to Load – a fancy way of saying that your car comes with a three-pin socket to power many of the things that I would feel essential when camping. Like heating!And with trips to see an elderly relative in Lincolnshire becoming both more frequent and more essential – with hotel bills every time I go – I began to think there just might be something worthwhile in having a TentBox.I should also point out that as well as a natural aversion to camping, I also have an natural aversion to anything that arrives in a flat pack. And yes, a TentBox does arrive in, well, another box.Installing a TentBox on the hottest day of the year maybe wasn't the brightest idea (Steve Fowler)However, apart from manoeuvring a large, heavy object when it was delivered, this lazy and cynical journalist was pleasantly surprised when my TentBox arrived.There are various flavours of TentBox, all designed to sit on your car’s roof rails. They range from a simple two-person TentBox Go for just under a grand, which apparently will open in just 60 seconds, all the way up to an auto-opening TentBox Cargo that not only will sleep 2 people, but also carry your bedding on top of the car, and let you stick a bike or surf board up there too. That one costs £2,499 – and if I’m honest, I thought TentBoxes would be more expensive than that.I went for the two person TentBox Lite at £1,349 – let’s just say the equivalent of ten nights away in a reasonable hotel. But with the TentBox there’s a whole lot more fun in store, and if you go for the TentBox Lite XL it claims space for four (obviously close friends). That one would cost you £1,999.I’m not sure what the Lite stands for, but a TentBox is bloody heavy, especially when manoeuvring on top of your car. It’s a two-person job and requires a fair bit of strength.The good news, though, is that it’s pretty much ready to go out of the box. There are just a few bits and pieces to attach – like the ladder and the cover – with an excellent 13-minute video that explains how to get the TentBox from the box to the top of your car, ready for your first night under cover.It all seemed so simple, even the heave to get the TentBox on top of the big Hyundai wasn’t too bad. Everything’s supplied, apart from the plasters to take care of scuffed knuckles. The TentBox Lite has room for two, but it was luxury for one (Steve Fowler)It took me longer to fit the u-plates, sliders and nuts and bolts than it did to do anything else with the TentBox, and there was plenty of swearing. TentBox supplies a handy spanner, but after fitting the first of the four u-plates, I’d have happily paid extra for TentBox to do the fitting for me, or to get a powered device to tighten the nuts.I can see why so many people leave their TentBoxes on top of their cars all summer, although I’m one of those people who always tells you to take anything off your roof when you’re not using it, in a bid to save some fuel.That said, I didn’t notice any real reduction in the efficiency of the Ioniq 9 with my sleeping quarters on the roof. In fact, I’d be lying if I said I really noticed that I had a TentBox on top even when driving on the motorway. As anyone who’s driven their car with roof rails will know, there’s already a fair amount of whistling that goes on, but it was no worse with the TentBox in place. And the car’s efficiency seemed as good as ever, with just the usual quick charge required on my way home from Lincolnshire.V2L (Vehicle to Load) and a three-pin socket in the Hyundai Ioniq 9 made camping easier (Steve Fowler)The promise of a TentBox is that you can pretty much pitch up anywhere to spend the night – with the landowner’s permission, obviously. I chose the car park of my Uncle’s now dormant business in Lincolnshire – a grassy, secluded spot with a handy outside toilet a few yards away.It really was as simple as stopping, releasing some straps, unzipping the TentBox cover, pulling the ladder out and folding out the TentBox. The tent pops up automatically and all I had to do was fit some rain cover poles before the really exciting bit – trying it out.Just to remind you, I’m not a camper, so was a bit confused by the windows with their flyscreens and covers to block out the light, but soon worked that out and decided to sleep with a view of the stars directly above me. As for the mattress that simply folds out with everything else – well, that was surprisingly comfortable.Climbing the ladder seemed a bit strange at first, but when you’re up high you just get to enjoy the view more. And it felt super-secure, too – no wobbling around, the Hyundai just stayed really stable underneath and I soon forgot that I was the best part of six feet off the ground.I had travelled prepared, too, with an electric heater. But the weather was warm enough for just a sleeping bag overnight. I did use the Ioniq 9’s three-pin V2L socket to charge up my laptop so I could watch a bit of Netflix into the evening, but my eyes soon got the better of me and I nodded off only to wake up in the early hours regretting drinking so much water before bed.Having the TentBox on top of the Hyundai Ioniq 9 didn't seem to affect efficiency too much (Steve Fowler)I wasn’t planning on a trip down the ladder at 1am, but it was fine. A quick pee, back up the ladder and asleep again before I knew it, with only the distant rumble of the occasional car passing up the road and an occasional baa or moo from the sheep and cows in nearby fields.What I wasn’t expecting was crows to wake me pretty much as soon as the sun came up, but it kind of added to the romance of the whole thing just knowing that I was at one with nature – and a Hyundai Ioniq 9.And here’s the bit I wasn’t expecting… I fully intended to do one night in the TentBox for the purposes of research, before finding somewhere with a more solid roof for my second night away. But I didn’t bother. The local pub meant I could get fed without having to pack everything up to drive somewhere, and I managed to keep myself busy sorting stuff out for my uncle during the day, so enjoyed a second night in the TentBox before heading home.I did get the help of a friend to remove the poles from the rain cover and flip the TentBox back over onto the car, then refit the cover – which stays partially in place – and with a bit of zipping and strapping I was ready to go again.So, am I now a camping convert? Well, yes – if it’s as easy and comfortable as this, and on top of a car, I’m all in. I’m also thinking of a TentBox World Cup party somewhere a bit crazy. With the power socket that many EVs have I could set up an electric barbeque and a big screen telly for a bit of football fun. Now that sounds like a plan.