Actually, while Clarion did buy McIntosh's car audio rights, it's all still built in Binghamton, NY. I've been to the factory and seen both the home audio and car audio manufacturing lines. That said, the separates in your car are of their "butterfly" series, which are almost identical to the aftermarket butterfly separates that a high end car stereo shop would sell to you. If you have a local *HIGH END* dealer, perhaps they can get a line on some for you. You're also welcome to call them in NY, or check eBay for McIntosh separates with butterfly tweeters.
Having worked for two different McIntosh dealers, both home and car, trust me on this one. Also, my mother has a 2004 OB Sedan 3.0 H6 with the McIntosh system, so I know what's in it.