New drive and old VWs don't mix

Thanks for all the suggestions.

I think the sealant is the way to go.

 

water down some brick acid from Jewsons. Will come off.

also good for cleaning really dirty alloys (as a one off)

 

Cement or lime over the oil patch and it will soak up the worst of it, then it will gradually fade.

 

Why spend money? Throw a small sheet of plywood or thick cardboard under the engine.

Job done.