You can still wire directly to the battery but this will involve a lot of work (taking the spare out and removing the air suspension pump)

__________________
BMW 1M 2012 - Current
Jeep Grand Cherokee Limited 2011 - Current
BMW E93 330i Convertible 2009 - Sold
BMW E46 320i 2004 - Sold
BMW X5 4.4i 2002 - Sold
VW Golf GTI 2000 - Sold
BMW 740i 1996 - Sold