Not sure with 2008 models, but with 2007 privacy glass only came with the rear climate package. The factory tint level is 35% for all the windows (rear sides amd rear).

Here are some pics of my X5 with 40% tint on front passenger and 40% over the factory tint (photos 408 on are shots of the tint.)
http://members.dslextreme.com/users/hoiya/X5

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[B]2014 Cayenne Turbo S[B]
2007 X5 4.8 - Titanium Silver , Black Leather, Premium, Prem Sound, Sport, Rear Climate, Heated Seats, Running Boards, Lux H8, GP Thunder Fogs
2003 BMW Z4 3.0si (retired)