But you may notice, as you look around you, that none of these dynamic and engineering weaknesses have been a handicap to high sales. For all their failings, Ford's XR-series Fiestas and Escorts have become national icons, and gained aspirational status. Part of the genius of Ford is that it knows how to make its quicker products look the part, and how best to market them.
The Fiesta XR2, and latterly the XR2i, illustrate perfectly how well flash can cover up the lack of dash. The carburettor models, in particular, (those without the tell-tale 'i' on the end of their labels) were ghastly little heaps. They had asthmatic performance, a loutish engine note, spine-crunching ride quality and zero character. Things improved slightly with the arrival of the RS Turbo but, despite being fast and, one must admit, perversely likeable, even this model was too ill-mannered to be taken seriously.
Yet they had all the necessary swagger, sitting squat on wide, low-profile tyres, their superficial bodywork muscle beefed up with add-on plastic skirts and wheel-arches. Looking the part was more important than actually playing it, and the critics be damned.
But suddenly the Fiesta has come good. Engine size has been increased from 1.6 to 1.8 litres, the suspension and steering have been revised, and the turbocharged model has been dispensed with. The engine is the same 1.8-litre, 16-valve 'Zeta' unit fitted to the Escort range and, like the Escort, is available with two power outputs - 105bhp for the XR2i, and 130bhp for the RS 1800.
RS stands for Rallye Sport, a handle Ford has applied to its quicker models since the Seventies, when the company enjoyed tremendous rally success. The RS 1800 is what the fasta-Fiesta should have been like all along. The baby Ford can now be considered a worthy rival to the current class leaders, the Peugeot 205 GTi, and the Renault Clio 16V.
More than any other factor, it is the engine that is responsible for the Fiesta's new-found stature. Although the RS 1800's power is not as great as the old RS Turbo's, it is more usable - the turbocharged unit suffered from excessive power lag. The new car is also considerably more couth. Harshness has been the bugbear of Ford engines for years, and although the Zeta is not exactly buttery smooth at the top end, it is no longer offensively rough or loud.
What the RS 1800 does not have is quite the pep of either the 205 or the Clio, both of which are puppy-dog eager. But it isn't far behind when you're in the mood for fun. A particular advantage the Ford has over the 205 becomes apparent when you simply want to potter about. It has enough strength to pull you along quickly but relaxedly, whereas the 205 is permanently manic.
The good news is not confined to the engine. Suspension modifications have taken most of the thud 'n' thump out of the ride quality, although potholes and ridges still cause problems. The new Fiesta's greater suppleness (over the RS Turbo) also helps its handling; the stiffness of the older car meant it could be bumped off-line on poor roads.
Sharper steering makes the RS 1800 a more responsive beast than its predecessor, too, particularly when you're pressing on. Previously, Fiesta steering gear gave a rather relaxed response to inputs at the helm. Now, you get what you ask for - and without delay. At least, you do at higher speeds; at lower velocities some of the zeal evaporates. That's because there is no power steering option on the Fiesta, and in order to keep the weighting manageable for parking, Ford has installed a variable ratio steering rack - at low speed it makes the steering light but vague. As compromises go, however, it's just fine.
Inside, Ford has cleverly done just enough to make you feel you're zipping around in something special without much extra money having been spent (either by you or the manufacturer). The main contact points of the cabin - the steering wheel, the gear lever - are leather bound, and the seats are big-bolstered and sporty to clamp you in position. The rest of the interior, though, is just like any other Fiesta's.
Curiously, Ford has played a subtle game with the RS's external appearance, a body-coloured rear spoiler (as opposed to black) and a set of rather plain alloy wheels being the main visual signals separating it from the lower- powered XR2i. Not so long ago, the RS badge would have been an excuse for Ford to lay on the macho look. I'd like it to look more distinctive, however.
It's odd to be even thinking in terms of owning a fast Fiesta. Until the arrival of the Zeta-power cars, I'd have been about as keen to be hit by one. It's good to report that the Fiesta's abilities have finally caught up with its reputation.
Citroen ZX 2.0i Volcane, pounds 12,575
It's a class above the Fiesta, but a rival on cost. Spacious, handles well, but hasn't the RS's zip. Not as much fun, either, but makes great family entertainment.
Renault Clio 16V, pounds 12,336. Best all- rounder in the class. Livelier than the RS and more spirited. Handling is excellent. Looks the part, and is.
Peugeot 205 1.9 GTI, pounds 12,475. Out-guns and out-funs the Fiesta, but its sheer vivacity can be tiresome and its transmission snatches in traffic. If you can live with these foibles, it offers unbeatable driving pleasure.
Ford Fiesta RS 1800 pounds 12,940.
Engine: 1.8 litres, four cylinders, fuel injected, with 16 valves. Power: 130bhp at 6,250 rpm. Performance: top speed of 124mph; goes from 0-60mph in 8.1 seconds. Average fuel consumption: 28-34mpg on unleaded petrol.