I’d like to claim the idea for myself, but it came from an aside in a conversation about something else entirely with Ariel boss Simon Saunders. He mentioned in passing that while they were testing their Nomad, someone had casually timed its progress over a stage and thought its pace similar to that of a Group N rally car.

Had I not known Saunders for many years, I’d have dismissed it as puff, the kind of comment we hear quite a lot: a big, improbable claim couched in terms broad enough to offer plausible deniability should anyone ever put it to the test, which of course they never would. Except that’s not his style.

But could a rear-wheel-drive road car with a normally aspirated 2.4-litre Honda motor really keep pace with a purpose-built four-wheel-drive turbocharged rally car complete with anti-lag, an electronically programmable centre diff and the kind of suspension that could make the surface of the moon feel like the M4 motorway?

At times like this, it helps to look at it from the other perspective, and we needed a Group N car to do it. To the rescue: well-known motorsport pundit Tony Jardine, who has been a rally driver for 40 years and will in two weeks’ time take part in his 20th Rally GB, when he will be driving a Rally Hire Group N 2007 Mitsubishi Evo IX.

This is the same car in which, two years ago, aged 61, Jardine won his class in Wales Rally GB, navigated not by some seasoned pro but Olympic gold medal-winning skeleton bob racer Amy Williams.

And it’s true that the Evo does have a lot of tricks under its standard skin but so, too, does it weigh almost 1400kg – not far off double the weight of the Nomad, even with the Ariel in full off-road configuration. And because of the Group N regulations, the Evo’s engine is not a 400bhp flame-thrower, but a standard road motor (save, I believe, toughened big-end bolts) breathing through a 33mm restrictor, limiting power to around 240bhp, far less than a bog-standard showroom Evo IX and a paltry 5bhp more than the Nomad. Would a power-to-weight ratio barely half that of its opponent not prove an impediment too great even for a proper rally car to overcome?

The truth is, we didn’t know, so we headed to the Sweet Lamb Rally Complex in mid-Wales to find out.