Are running costs on a Boxster S going to exceed a Z4m?

[Hark]

Straight question

Answers on a post card.

Read lots of reviews etc and threads on here.
Seems that Porsche is more likely to throw your a curve ball repair when you werent expecting it with a few grand price tag.

[Don]

I expect they're roughly equivalent. I've run a Boxster S for about nine years now and nothing major has gone wrong but it hasn't exactly been cheap either!

M cars have always had far higher servicing costs than their nearest ordinary BMW equivalents. To be honest I'd reckon the best value car is a Z4 three litre or something.