When half the contents of the Atlantic Ocean fell - I could have sworn at the time - on my little corner of the earth recently, the thing that always happens on these occasions happened again.To explain: there's a short stretch of fairly steep gravel road leading to my house and those of my immediate neighbours. What with one thing and another - people going to and from work, post vans delivering the mail - there are maybe thirty or so journeys up and down this road each day. Visible ruts are rare, but all those wheels soften up lines on either side of the centre. When the monsoons come, the looser gravel is washed down the hill, and the road turns into an assault course.On this particular occasion I was glad to be driving a Renault Scenic RX4. I was glad again a couple of days later when several tons of new gravel were deposited on the drive about two minutes before I had to leave home. If I had been driving a normal saloon car I would have been stuck, but with the RX4 I was able to cross over them, to appreciative cheers from the guys with the shovels.But that was where the gladness stopped. Although I do not form part of the target audience for the Scenic in any of its forms, I can quite see why the mini-MPV version, and the various rivals which have sprung up like mushrooms since its launch, are such a hit with their customers. It was a brilliant piece of work by Renault to identify this possible new market, convert the Megane hatchback into something excellently suited to it, and then sell it in such phenomenal numbers.Whether or not there is, as Renault believes, another new market for cars which combine the features of a mini-MPV and a "lifestyle" off-roader from the Honda CR-V/Toyota RAV-4 school is something that will become apparent over the next couple of years; it's too early to say right now. But I do not believe that Renault's execution of the concept, in the form of the Scenic-on-stilts RX4, has been at all well done.That became clear within yards of driving the car. Its huge ground clearance has compromised the Scenic's stability to the point where I felt as if I was sitting on a giraffe balanced on a beach ball. There is little question of the RX4 ever being driven quickly - it's just not that kind of machine, though its two-litre engine gives it quite reasonable straightline performance - but even at gentle cornering speeds I could imagine that in an emergency situation it could easily fall over (I wonder if a certain Scandinavian magazine has performed the infamous "Elk test" on this car yet, and, if so, exactly what happened when it did).Most of the science of suspension set-up is concerned with weight transfer. The less you have of this the better, but the RX4 comes with oodles of it as a standard feature, hence the uncomfortable feeling on corners. Weight transfer can also be bad news under braking, and I don't fancy the idea of having to do an emergency stop in this thing.All the usual Scenic practicality is in evidence, and the RX4 can certainly tackle ground which would force its less adventurous stablemates to a standstill. But it's too much of a compromise, perhaps because it is now one development too far from the Megane on which it is loosely based.A four-wheel drive Scenic with a more modest increase in ground clearance would probably do everything that an RX4 owner would realistically require of it, while remaining safer and more stable on tarmac. As it is, though, I reckon Renault has overstretched itself. This is a car which needed a bit more careful thought in the early planning stages.Second opinion: From a styling point of view, what I didn't much like about the RX4 was the rear-end bulge covering the spare wheel which, unlike its two-wheel drive counterparts, the four-wheel drive model can't accommodate inside. Otherwise - agreed - all the usual Scenic practicality is there, from the ingenious stowage areas to the remarkably versatile seating. I thought the RX4's extra weight affected its performance at places like the long drag up to Shap Summit, but that is not this car's natural habitat. It's intended for a specific and quite tiny niche market. I know people who are moving to a remote house in the hills, in an area where the winters are often quite harsh, and their farm-track approach is going to be rough from January to December. They mulled over their transport requirements and decided on an RX4. It's a special-situation car, and I think it'll do them fine - admittedly, as long as they resist the temptation to tackle the winding farm track like a rally special stage. Ross Finlay. Engine 1998cc, 4 cylinders Power 140bhp Fuel 29.7mpg Acceleration 0-62mph: 12.3 seconds Top speed 109mph Price £18,400 Details correct at publication date