Some of them are oil filled. My e70 is up for two more new bushings only about 15 or 20k miles after the last set went in. On the e53 they hold up better but my wife just loves to hammer the brakes on the e70 (it seems to have the largest disk option available) and she got thru these quickly.

Not thrilled with that interval but I also need to change a few bushings in the LCA and refresh front diff fluid, so it'll be up off the floor for a day soon.

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2003 4.4i black ext./black int./black headliner (kid's runabout)
2014 535d X-drive, M package, silver/black interior

Sold but not forgotten:
2009 E70 35d, black ext./black int./black headliner (sold 2021)
2006 4.8iS Le Mans blue/cream int./black headliner, SOLD in 2012 sadly...

Other hardware:
2015 Cayenne S (wife's new DD and definitely wroooommmmm)
2016 Tundra 1794 edition crew cab, luxo hauler
2005 Tundra crew cab, weekend hauler. Sold after 150k very happy miles.