Passat W8 with a manual.

It can’t even get 20 MPG combined (15 city, 22 highway, for 18 combined), parts are unobtainium, it’s a Volkswagen so you’ll need those parts, and it makes less power than the 3.6 VR6 that replaced both it and the 2.8 V6.

But, well, if you open up the exhaust... it’s a flat-plane V8 with VR6 warble, just listen to it:

The Taurus Sports Racing Lola B2K/10 with a “Caterpillar” engine at Le Mans:

This was a project to take advantage of the new diesel rules in LMP1 - Audi and Peugeot had lobbied for them, and they took effect in 2004, but the R10 wasn’t ready until 2006, and the 908 wasn’t ready until 2007.

But, instead of developing a racing diesel engine, they decided to use a new road car engine that was all-aluminum and quite large displacement, the Volkswagen 5.0 V10 TDI. Volkswagen wasn’t willing to sell the team an engine - after all, it’d compete against Audi’s own diesel project - so they instead bought a Touareg, and pulled the engine out. The Caterpillar branding is because Caterpillar did the tuning, IIRC.

It didn’t actually work out - turns out that a Lola B2K/10's gearbox doesn’t like being subjected to the torque of a tuned 5.0 liter diesel. But, still, an audacious project, and I have to admire the attempt (even if I’ve massively soured on diesel technology).

(As an aside, wow, the Lola B2K/10 is fugly.)