Wondering if any one has had to deal with a rear main seal (engine) leak on an E-39 540i? My indy tells me they have seen quite a few of these. Based on the Bentley's repair manual it looks fairly involved. I was quoted almost $1K for the repair (about 12 hours of labor and $150-200 in parts. Fair/reasonable? If I go ahead with this repair (which I probably will since it will only get worse) is there anything else - repair/replace wise - I should get done while it's apart adn in the air? Thanks.