Are you insane, not yes but HELL YES...LOL!! But hey you already own one (is it a 6cyl or 8cyl?) so you know what to expect, I think you'll be fine. By the way there's one other member who has/had his and her E53s, but the repairs were killing his wallet so he finally let one go, and I believe he was thinking about letting them both go, do a search and you can his find thread. Looks good!

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2002 X5 4.6is
1999 C5 Corvette
1992 Mitsubishi 3000GT VR-4
1994 Kawasaki ZX-9R
2005 Mazda 6 Wagon (Wife's)
1991 Mitsubishi 3000GT VR-4