If you ever feel in need of a reminder of just how good modern sports cars are, I can think of nothing more likely to provide it than a couple of hours at the helm of a Morgan Roadster. It may have a new name and engine, but the guts of the car — its steel chassis, wooden frame and live rear axle — have not changed significantly in half a century.

Compared with any Porsche, BMW, Lotus or TVR you might buy for similar money, the Roadster is almost comically incompetent. The brakes are poor — they have no antilock system and lock up far too easily in the wet — ride quality is best not talked about, and levels of grip are inconsistent. It is maddeningly uncomfortable, slightly frightening if you push it hard and, although no slouch, point to point it really is not that quick.

To make matters worse, this car exists to replace the Plus Eight, a machine beloved of thousands since it came to market in 1969 with a beautifully burbling 3.5 litre Rover V8 engine beneath its bonnet. The new engine is a 3 litre V6 Ford unit more usually found under the bonnet of the Mondeo ST220. Installed in the Morgan it sounds distinctly flatulent. Anyone looking for a true rival to any of the above-named marques would be an idiot even to look at one, let alone part with £35,231 for the dubious pleasure of its company.

Which is why I’m still wondering why I quite liked it. And my conclusion is that I love old cars, not for reasons of mawkish sentimentality, but simply because they give you something to do. A new Porsche 911 is an astonishingly capable car, but threading your trolley past the fruit and veg at Tesco on Saturday morning offers a greater test of your driving skills. By contrast, drive a 40-year-old 911 hard cross country and, unless your concentration is total from the start, there’s a reasonable chance you won’t even make it. And that’s what I call a challenge.

Most will see the current level of refinement as a good thing, and I’d not deny it. But until you have experienced the level of driver involvement required simply to keep an old crock on the road when you’re in a hurry, you will remain a stranger to one very real form of driving pleasure.

It’s born of the knowledge that you, the driver, really are making a difference. By driving smoothly, thinking ahead and understanding the many faults and idiosyncrasies of your car, you can go faster, stay safer and at journey’s end experience a sense of pride you’ll not find in any modern car that does it all for you.

The problem is that old cars are slow and prone to leaving you on first-name terms with the man from the AA. The Roadster’s proposition is to package all the old-style thrills into a perfectly reliable, beautifully built and really rather quick car.

And it just about pulls it off. The V6 may sound less distinguished than the previous V8, but it has brought a new level of performance: 0-60mph in 4.9sec and a top speed of 135mph. In this it is a joy to drive, but in other respects, and by modern standards, it’s tricky in the extreme.

The suspension feels as primitive as ever, but once you’ve plucked up the courage to find out what happens when you tread too hard on the throttle in a tight turn, you discover it reacts in a faithful and entertaining way — so long as you’re not travelling too fast in the first place. This is a car for which the phrase “slow in, fast out” could have been coined.

Of course most Roadster owners wouldn’t dream of driving their Morgan so energetically. What they’re after is a magnificent down-the-bonnet view, body panels not mechanically pressed from steel but bashed from aluminium by a man with a hammer, a white coat and pencils behind his ears. They want a small steering wheel with three drilled alloy spokes and a bank of old-style instruments. And they want it from a company that has been building cars in the same place and in the same way for the thick end of a century.

And that’s what makes Morgan unique. The Roadster is not a pastiche of an old car, nor even a lovingly re-created replica, for that would suggest not only a lack of continuity but also a behind-the-scenes modernity it simply does not possess. Like every other Morgan, it is built entirely by hand in a factory that first started producing Morgans in 1910.

Go there and it is like a time warp — a world of chisels, planes and lathes where cars are lovingly created by the hands of craftsmen, not expertly assembled by the mechanical arms of robots.

I came away from my morning in the Roadster slightly dazed — it had been a long time since I’d driven a car so startlingly easy to criticise.

But as I drove home in my modern tin box, I could not deny that I had enjoyed myself and now, a couple of weeks and lot of Christmas cheer later, I still find myself smiling at the memory.

For all its faults, it made me feel good. It indulged and involved me in a way few modern cars could, and while the fun it provided was slightly perverse and mildly masochistic, fun it undoubtedly was. Put it this way: I don’t want one even a tiny bit, but I understand entirely why someone might. Which is a more than I can say about a lot of the cars that I drive.

Vital statistics

Model Morgan Roadster
Price £35,231
Engine type Six-cylinder, 2967cc
Power/torque 223bhp @ 6150rpm, 206 lb ft @ 4900rpm
Transmission Five-speed manual
Fuel/CO2 28.mpg (combined) / 232g/km
Performance 0-60mph: 4.9sec / Top speed: 135mph
Verdict An effective, comprehensive update
Rating 3/5

The opposition

Model TVR Tamora, £36,698
For Huge performance for the money, characterful
Against Not exactly attractive, handling slightly crude

Model Porsche Boxster S, £38,720
For Very capable in all conditions, easy to drive very fast
Against The looks have failed to evolve with the car