Arias Pistons 12.5:1 Compression 82mm Bore Honda B-series on 2040-parts.com

GM's Ed Welburn walks Jay Leno through the Elmiraj concept's design [w/Video]

General Motors' vice president Global Design Ed Welburn stars in the latest of the 'Jay Leno's Garage' YouTube series, running the talk-show host through some of the new Cadillac Elmiraj concept's design features and what it means for the brand's future. We get a look at all the classic Cadillac design cues such as the vertical headlamps and tail lamps as well as the central hard crease that Welburn says is "important in every Cadillac". Leno and Welburn then move onto the Elmiraj's features, such as the large doors' integrated handles and the slimmer A-pillars before a more in-depth look at one of the concept's most striking features – the grille.

Audi A1 prices start at £13,145 in UK

Audi’s new A1 supermini has gone on UK sale today, priced from £13,145 for a 1.2 TFSI SE trim model to £18,280 for a range-topping 1.4 TFSI auto. That pitches the A1 slightly above the Mini, whose boggo First three-door kicks off at £12,620. But study the two rival supermini ranges from Audi and  BMW more closely and you’ll see they’re quite evenly matched.

CAR interviews 'Mr GT3' Andreas Preuninger

The latest Porsche 911 GT3 boasts an all-new 469bhp 3.8-litre flat-six and is quicker than the legendary GT3 RS 4.0, but fans of this hardcore icon have voiced their concern over its new dual-clutch PDK gearbox and its steering (both the electric rack inherited from the 991-generation Carrera, and the new rear-axle steering).  Ahead of the 911 GT3's unveil at the 2013 Geneva show this week, CAR had exclusive access to the car, and to the man who headed the team that engineered it: Porsche's head of GT series production Andreas Preuninger. The controversial new Porsche 911 GT3 Preuninger built the first 996 GT3, and has been doing his  job for the past 12 years. We asked him all about the new GT3, including those controversial issues.