Despite the sports exhaust and drop in ride height, you would be pushed to spot the ST185 in a packed car park. But that’s part of its appeal. There are no frills or glamour, simply a set of brilliantly engineered motorsport upgrades for those who can look beyond the ST’s dated design. While price is clearly an issue, the performance upgrades transform a fun but ageing hot hatch into a genuine seat-of-the-pants experience.

Time is running out for the Ford Fiesta. With the all-new Verve set to take a bow at the Geneva Motor Show in March, the blue oval is gearing up to write the next chapter in the history of its small car line-up.

But what will become of the current model? A lick of paint and an interest-free finance deal is how most manufacturers usually send off a car in its final year in the showroom – but not Ford. Instead, the firm has teamed up with Mountune Racing to develop a performance pack that looks sure to give the Fiesta the send-off it deserves, with a special flagship version of the hot ST.

To further improve the appeal of the package, the kit can be applied in two distinctive steps. Stage 1 features a high-flow induction system, performance exhaust and engine management tweak, lifting the power of the 2.0-litre normally aspirated Duratec engine from 150bhp to 165bhp.

Stage 2 goes further by adding new camshafts and valve springs to liberate 185bhp. Both can be fitted to new or used STs, but best of all, they don’t affect your existing manufacturer warranty and come with a year’s cover of their own.

Our test car arrived with the Stage 2 performance upgrade, as well as sports suspension supplied by German tuning expert KW and figure-hugging Recaro sports seats.

With no cosmetic additions, the tuned Fiesta ST185 is refreshingly discreet. But the strength of the hot supermini has always been its sweetly balanced chassis and crisp steering. On the road, it quickly becomes clear that the suspension upgrades build on that, with the non-adjustable KW springs striking a perfect balance between sportiness and ride comfort.

The steering is very accurate and turn-in sharpened, with the 30mm drop in ride height adding even more mid-corner control to an already
light and nimble package. And then there’s the performance of the 185bhp engine. It really does feel a full second quicker from 0-60mph than the standard car, as Ford claims with its 6.9-second time. But more than that, it’s responsive and willing to rev, especially above 4,500rpm.

Thanks to those new sport camshafts, it rasps and pops like a junior rally car. The only real niggle is that the addition of a sixth gear would improve refinement at motorway speeds.

However, the biggest problem with the ST185 is its price. Ford has set the bar high at £1,435 for the 165bhp Stage 1 system, and £1,838 for our 185bhp Stage 2 kit. And if you want to add all of the upgrades of our test car, you need to spend a further £605 for the lowered suspension and £1,951 for the Recaro seats.

Add the cost of these extras to a standard ST’s £13,595 list price, and you’re looking at an £18,000 Fiesta. And that’s before you’ve considered having the parts professionally fitted – or accounting for the impact on your insurance premiums.

If Ford had produced a special-edition ST185 model instead, it would have made more sense. A final swansong with all of the exciting extras bundled together and a price closer to the £16k mark would have really given the Renaultsport Clio 197 something to worry about.

As it is, the performance upgrades are a more tempting proposition for those who already have a Fiesta ST parked on their driveway. Ignore the comfortable yet unnecessary Recaro seats, opt for just the sports suspension and Stage 2 performance kit, and you’ll have a genuinely exciting car. And while it will be far from refined, it’s sure to put more smiles on your face than any other supermini hot hatch.