Just to clarify your point about cabin air filter replacement: I have read horror stories about how difficult it is to replace these on Sevilles and Eldorados and I'm sure your point is well taken. On 2000 and later Devilles, however, cabin air filter replacement is quite easy. The filter is located beneath an access panel under the hood, on the passenger side, just forward of the base of the windshield. The filters are kind of pricey ($45 at Pep Boys, $65 at dealers). When I replaced mine, I noticed a significant increase in air flow through the vents and they do help keep dust and pollen out of the cabin.