Simon, I felt sure, must have been wondering what I was playing at. Among his other talents, Simon is an experienced and talented rally navigator, and he was sitting alongside me in the FQ-340, helping to guide me along roads I had never experienced before by reading them off a series of Ordnance Survey maps he had brought with him. It wasn't quite the same as having pace notes, but it was very effective, and as I tootled through a series of long, fast left and right sweepers - wary of possible tractors, oncoming traffic and speed cameras - I felt I wasn't using his service as much as I should. Then I glanced at the speedometer and found I was doing 96mph.It was a good illustration of the care you have to take behind the wheel of the most powerful Evo IX. It's very, very fast car, even when you think you are going slowly. Great concentration is required to keep it within speed limits, and there's a risk that even if you have a clean licence when you buy the car you'll be banned from the roads before it needs its first wash.The Evo IX is very closely related to the Evo VIII, but despite recent implications in the media it's not just the same car with a different badge. New exterior features include a revised front end, a hollow carbonfibre rear wing (the VIII had a solid one), revised front and rear lights and new 17" Enkei five-spoke alloy wheels. The very familiar two-litre turbo engine, now 18 years old, has been tweaked yet again, this time with the addition of variable valve timing which allows the Evo to operate calmly from as low an engine speed as 1500rpm.As with the Evo VIII FQ models, the engine comes in three states of tune. The FQ-300 has the "standard" unit, the FQ-320 gets an upgrade kit developed by Ralliart and HKS, while the FQ-340 - the one tested here - has the same kit but with a remapped ECU. The result is 345bhp, a top speed limited to 157mph and a 0-62mph time estimated by Mitsubishi to be 4.3 seconds.This is more or less World Rally Car performance, and it's matched by the fact that the Evo IX is about as appealing to drive in normal road conditions as a World Rally Car would be. The colossal exhaust tailpipe creates a resonance which thunders through the bodyshell and makes this the noisiest standard production road vehicle I have driven since the 1986 Ford Orion diesel. My colleague Graeme Giles, who has both driven and been driven in an FQ-340, reports the curious situation that the car seems much noisier on the passenger's side than on the driver's, for reasons neither of us could fully understand.The noise is painful, but it does at least take your mind off the terrible rear visibility (that big rear wing is in the way) and the crashy ride quality. But let's not kid ourselves here. Nobody in their right mind would buy an Evo as their sole means of transport. It's a toy - a car to be used only when the opportunity to drive hard presents itself.For most owners that opportunity will involve a track day, and it is really only in these circumstances - or those of a motorsport event, if you feel brave enough - that the full potential of the FQ-340 becomes available. Even on brilliant roads with good sightlines and minimal traffic, you can't remove the leash entirely. There just isn't enough room or enough safety margin. Anyone who tells you they can drive an FQ-340 flat-out on the public highway is either not much of a driver or a moron you won't be hearing from for much longer.That's not to say you can't enjoy the car on quiet roads, though. You just have to approach the matter differently. I found I was changing up at 5000rpm, well short of the 6800 where the full 345bhp is produced but still enough to produce fantastic acceleration. I was also happy to drop below 3500rpm, the point at which the engine's character changes from impressive to Oh My God. Exiting a corner on full throttle at low engine speeds provides what I suppose you would call a form of passive traction control, letting you drive hard without getting the full blast of power until you've straightened up.The engine is so potent that it has an enormous effect on the car's handling, despite the brilliantly set-up (and recently revised) suspension, the four-wheel drive system and all the electronic controls. This is not a problem as long as you know what you're looking for. In particular the Evo IX has more front-end movement than I remember from previous versions, and you have to let this settle on the entry to a corner before applying the power, otherwise you'll have a small but annoying dose of understeer to deal with.If you avoid this, applying power will then help the back end follow the front through the corner - a matter of weight transfer rather than an actual slide, unless you really overdo it. This feels very satisfying, but the same responsiveness to power has a slight downside. A comparitively small lift on the throttle can sometimes cause the engine to shut off abruptly, and if you happen to be in mid-corner when this happens the front end will dart on to a tighter line. Gearchanges have the same effect, as I found to my alarm when exiting a roundabout with a Citroen Picasso to my immediate left.At just short of £33,000, the Evo IX is a very expensive toy, though undoubtedly a very effective one too. Dedicated Evo fans do not, however, seem to be fazed by the cost (perhaps because it's practically impossible to find the same thrills for the same money elsewhere). The test car was actually worth just over £1000 more than standard thanks to the addition of various optional extras, most of them fairly esoteric.For example, you can spend a three-figure sum on a small piece of metal known as a Gurney flap. This is an add-on to the trailing edge of the rear wing, and it's named after the legendary race driver Dan Gurney, who was the first to use it. Being able to quote this in the pub is probably every bit as important to Evo owners as the extra downforce it was designed to provide.Other extras include Ralliart mats, a Kenwood radio/CD (like you're going to be able to hear it over the noise of the exhaust) and - the one that really made me gasp and stretch my eyes - a carbonfibre surround for the electric window switches on the driver's door. That costs £118.42 plus VAT, and before driving the car I expressed astonishment that anyone would pay so much for so little. "But people buy it," said the Mitsubishi lady, and wandered off, smiling happily. Engine 1997cc, 4 cylinders Power 345bhp Transmission 6-speed manual Fuel/CO2 21.6mpg / 334g/km Acceleration 0-62mph: 4.3 seconds (estimated) Top speed 157mph Price £32,999 Details correct at publication date