I recharged the AC on my 2003 e53 in 2007 or 2008 at the dealer. They did the whole evac and refill. It worked fine for a number of summers, I seldom run it in the winter period.

Then in 2010 it stood around a body shop for several weeks to fix something minor while I was out of the country and when I got it back the AC was dead. I decided to recharge from a bottle I bought at an auto parts store and now we are another four summer seasons down the road. Started right up when the weather finally picked up a week or two ago.

So it can happen and not be a great big issue.....good luck.

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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.