More than 6,000 registrations add up to an unqualified success for a big American car launched a little over two years ago in a declining market.

But Chrysler believes a series of subtle changes are now set to pave the way to an even better showroom performance for the 300C.

At the very least, a makeover aimed at softening the model’s in-your-face personality should help the chunky saloon and Touring range hold on to its 4% share of the E-segment, now showing buoyancy after four years in the doldrums.

There’s not much new to see on the outside, except at the back where a reshaped bootlid now features a spoiler and a high-mounted brake light.

But open any door and there’s a marked difference as a decidedly urbane environment replaces brashness.

Given that the revitalised US maker now sees itself as a serious alternative to Audi, BMW or Mercedes-Benz, it’s no surprise to find a better-designed instrument panel and centre console, using satin silver highlights.

More supple trim is now used for arm rests and door panels.

Details like soft LED lighting reinforce the move upmarket – but the biggest improvement comes from replacing the garish dual-tone trim with just a single, darker interior shade.

In this guise, the 300C gets fresh appeal – and SRT-Design versions blending sports looks with the likeable regular diesel engine should win considerable interest even though they’re £5,000 dearer than the high-value lead-in cars.

Fact file

Price: £27,495-£40,995
Engine: 3.0-litre V6 diesel, 215bhp; 6.0-litre V8 petrol, 425bhp
Performance: 0-62mph: 7.6-5.0 sec; top speed: 143-168mph
Efficiency: 34.9mpg (official) 20.2mpg (actual) 215-330g/km CO2
Rivals: BMW 530d SE, Audi A6 2.7 TDI SE, Mercedes-Benz E280 CDI Elegance
Strengths: High equipment levels, competitive prices
Weaknesses: Love-it or hate-it styling