For a car built in such low volumes, and with effectively only one bodystyle, there are a simply astonishing number of variations on the theme of the Caterham 7.
You can have a 2.3-litre Cosworth-tuned lump with either 200bhp or 260bhp; a 2.0-litre Ford Duratec motor with 175bhp, 210bhp, or 263bhp; a 1.6-litre Ford Sigma with 125bhp or 150bhp; or you can even still get the venerable 105bhp 1.4-litre K-series Rover engine.
That's just the engines. You can also have a choice of three transmissions (five-speed, six-speed or six-speed sequential), De Dion or independent rear suspension, a variety double-wishbone set-ups for the front, and 14, 15 or 16-inch wheels.
There are even three different basic bodyshells: the classic standard car, the wide-body SV for the larger gentleman or lady, or the more sophisticated CSR.
You can't pick and choose freely between all these elements - the sequential gearbox is R500-only, for instance - but you get the point: there is, pretty much, a 7 out there for everyone.
As the name suggests, the Roadsport is the more comfort-oriented, less hardcore version, so features a windscreen and roof as standard, less hardcore suspension settings, properly adjustable non-bucket seats and a more 'traditional' cockpit. Our test car also had the longer, wider (and 25kg heavier) SV chassis, which we think suits the more 'everyday' nature of the 7 better. In all it weighed in at 575kg, some 60kg more than the R300.
So, though both cars have the same engine, they are clearly very different beasts, and aimed at very different customers. For that reason we decided to put the R300 in the hands of die-hard Caterham fan RacingPete, while the Roadsport would have the task of winning-over 7 sceptic Garlick.
Would the R300 live up to RacingPete's expectations? And could the Roadsport convince Garlick? Over to the subjects of the experiment...
RacingPete on the R300:
But this motorised torture chamber is not something I want to swap out of in a hurry. The sensations of roof-down, doors-off, pure-adrenaline driving is stopping me from going home and I wait at another traffic light with the push-button indicator loudly beeping - in the wrong direction.
Weighing in at just 515kg the latest superlight R derived Caterham delivers 300bhp per tonne. With performance figures to turn more exotic cars green with envy, this is a fun place to sit and, like its older siblings the R400 and R500, as close to a full motorsport experience on the road as you're likely to get.
Light weight-ness isn't all about those magic bhp per tonne figures; it's also the way the car transfers this weight through the corners. The car is immensely balanced and nimbly changes direction without too much concerns. With bespoke Avon CR500s at each corner, the speed you can negotiate roundabouts, hairpins and supermarket car parks is immense.
Garlick on the Roadsport 175:
Three years ago I spent the best part of a week with an Ariel Atom and from that moment I wouldn't really consider any other super lightweight sports car. I've driven a KTM since then and that couldn't change my opinion. And as for Caterhams? Well I had driven a few of them, mostly on track, and I just couldn't get my head around them. Usually I was spinning them off the track with my ham-fisted movements on the controls.
Heading home that evening I was looking forward to seeing what the fuss was all about, but to be honest I was still not expecting that much. Starting it up I was instantly happy with the noise it made from the side-exit exhaust a few inches from my ear. The gearbox was fantastic and the view across the headlights, watching the cycle wings move up and down, was rather special. Heading through the fairly light London traffic I was 'pointing and squirting' through gaps and generally having a ball. Other traffic let me out of junctions and everyone who spotted it gave a smile.
The next day was Friday, meaning I had the entire weekend to drive it. It rained, predictably, so on went the roof (which is a 30-second job and not as hard as people make out) and down the rain-soaked A3 I went with the little wipers working hard. Even that was fun; the cabin was spacious enough (well, it was the SV - Riggers), the wipers worked to a decent standard and I didn't get wet. There was a lot of heat inside the cabin, but it was liveable enough that I actually started to consider a Caterham as a daily driver. In fact I still can't think of a reason not to buy one. You simply cannot fail to be impressed by the way in which everything works together so well and the back-to-basics way that it is YOU that drives the car and makes it react. Who needs electronic aids?
In the days that followed, the sun came out and I spent more time sitting in the SV175 than I did on my sofa. It's that sort of car, you just can't help yourself and I will say right here that it is the best car in its class. New variants of the lightweight sports car come along with more power, more modern styling and more extreme performance but do you know what? You don't need it; why fix what isn't broken. You can keep your skinny lattes with an extra shot and vanilla syrup. I prefer to keep it simple with an espresso, small, effective and a true untouched original. Don't try and improve on it because you can't; perfection has already been achieved.