The wraps are slowly...

The wraps are slowly being peeled back on Jaguar"s new Big Cat тЂ“ the XJ. These teaser pictures were released at the Shanghai Motor Show, giving us our best look yet at the upcoming BMW 7-Series and Mercedes S-Class rival, which will go on sale before the end of the year.

As you can see, Jaguar hasn"t revealed much тЂ“ but the top-down view does show that the newcomer gets a panormaic glass roof for the first time. According to sources, this will be an option on the finished car.

It also boasts the same pronounced bonnet bulge as the XF, along with neatly styled bright red tailights. Described by Jaguar as being even more radical than the XF, the XJ gets a sleeker, more coupe-like roofline, which mixes with a low nose and high tail to result in a really sporty shape. See our scoop shots of the new XJ.

Two versions will be available with short and long wheelbases. Under

the skin is a totally re-engineered version of the current XJтЂ™s lightweight alloy chassis, boasting the XK coupéтЂ™s rear suspension, plus increased passenger space. Inside, the XJ will draw on the XF with a striking cabin. Jaguar says the XJ will introduce "the highest standards of personal luxury".

Under the bonnet, top-spec models will get a new 5.0-litre direct-injection V8 engine, which produces 385bhp in

normally aspirated form. A supercharged

version, pushing out 503bhp will be available too, although it is unlikely to be badged XJR.

However, a new 271bhp

3.0-litre twin-turbocharged diesel engine is expected to account for

the majority of XJ sales. This will be capable of returning an amazing

40mpg тЂ“ the same as the recently launched Diesel S version of the XF тЂ“

thanks to the new XJтЂ™s lightweight alloy construction.

The XJ will be officially revealed in London on July 9th, before reaching dealers before the end of the year. Potential buyers can register their interest at a special Jaguar microsite тЂ“ www.jaguar.com/allnewxj/