I’m a fan of the rear air springs only as the system is very easy to work on and uncomplicated. I also like the ride they give. They are also relatively inexpensive new from Arnott, and others I presume.

I don’t have the four corner system on my E53, but my wife’s Jeep had it and while it was great when it worked, once it began to leak it was hell to troubleshoot and parts are very expensive (front struts especially). I converted that Grand Cherokee to springs.

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Current
Original owner 2002 E53 X5 4.4i to 4.6i swap
2025 G06 X5 50e
Former
1972 Audi Fox
1986 Saab 900S
1996 BMW Z3
1998 BMW E36 M3 Sedan
2004 BMW E46 M3
2006 Audi A3 Quatro
1993 Mopar 318 Jeep Grand Cherokee
2015 V6 Jeep Grand Cherokee