I paid $1950 for a 4 year / 60K mile SecureCare warranty from Warranty Direct on my '03 Boxster in December 2007, when my car had 35,000 miles on it. Given that I drive it about 7,000 miles a year, I should get to 60K at right around 4 years, so my yearly cost is about $500, not "thousands". They've already paid for this year, as they covered a new window regulator and cam cover seal repair.
SecureCare coverage:
http://www.warrantydirect.com/secure_care.asp
They also cover the MAF, along with most other emissions related components.
Getting them to pay for major stuff requires that you have documented evidence of all Porsche-required service being performed at the required intervals. Also, from the experiences of others, you need to immediately address all external oil leaks, as WD has cited them as evidence of neglect when denying claims.