Ok the current vehicles:
BMW M5 V10 E60 - Mods - Tubi race exhaust 515bhp
Mercedes SL55 AMG - Mods - Stage 2 DMS tune with suspension tune 600BHP
Sierra Sapphire 4x4 Cosworth - Mods - Too many to list!! 400bhp
Ducati 916sp - Mods - Std 130bhp
Test a straight uphill road from corner rolling from 2nd gear (length unknown) then brake for corner, speeds acheived GPS:
1....Mercedes 108mph
2....Ducati 105mph
2....BMW 102mph
4....Sierra 95mph
All vehicles have fantastic brakes, so quite a realistic test, the merc would win hands down straight line onto the 208mph

The BMW would win handling, its just so good with T/C off S6 mode P500S, comes 2nd top speed onto 205mph. Merc is dangerous with T/C off due to no LSD and 600ft/lb torque!

With it on, its ok with the suspension mods but not BMW territory...Saff is great handler but sadly even with the massive mods can only come 2nd to the BMW top speed would be around 170mph at a guess here. Ducati stunning to 120ish mph but strangely beaten on my test by the Merc maybe i am a pussy on the bike? LOL....will pull to 155mph.
Not really interesting

i know

but my verdict:
BMW M5 V10 is quite simply the best car in the world with the best engine PERIOD.
Mercedes SL55 AMG looks stunning and comfort is great and straight line is mind boggling.
Saff is a great piece of automotive acheivement back in the 90's Retro now but has a solid place in my line up.
Ducati is without doubt timeless and the most beautiful bike on Earth, BUT is the most uncomfortable bike on Earth to ride slow

Not fast by todays std (this is 1994! but using a P8 ECU fuel injection via 2 x 803 injectors per cylinder is still up there tech wise) but can hold its own anywhere bar a motorway..lol.