The E46 was a very mature platform, very reliable. Relatively simple.

The E53 has more systems to fail, and they tend to cost more to fix when they do fail. Transmissions are one example. While it would have no trouble towing, and it is a great vehicle, it can't be directly compared to an E46 in terms of reliability and ease of repair.

If you go into it expecting to have to do typical repairs, as it will be a 5 - 7 year old vehicle, you will be fine.

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2007 X3 3.0si, 6 MT, Premium, White

Retired:
2008 535i, 6 MT, M Sport, Premium, Space Grey
2003 X5 3.0 Steptronic, Premium, Titanium Silver
2002 325xi 5 MT, Steel Grey
2004 Z4 3.0 Premium, Sport, SMG, Maldives Blue