This is Alpina's new B5 Biturbo, which has been given its public debut at Goodwood's Moving Motor Show.
The B5 uses a tuned version of BMW's 4.4-litre twin-turbocharged V8 powerplant, producing 500bhp and 516 lb ft of torque. That's enough, claims Alpina, for a 0-62mph time of 4.7sec and a top speed of 191mph.
Alpina often shies away from using the same powerplants as M division models, but barring some differences in the inlet system, the B5 will go head to head with the forthcoming M5 on engine choice. Its transmission will be totally different, though; the B5 uses a modified version of ZF's eight-speed automatic gearbox, whereas the M5 is widely tipped to use a dual-clutch unit.
Alpina claims the B5 offers class-leading fuel economy and CO2 emissions, at 26.1mpg (combined) and 252g/km respectively.