To me the badges actually look good, certainly they don't look bad. There are not too many of them and they are not a odd shape/size/style. If you take them off it's not like anyone who is at all interested in cars would not know what the vehicle is.

Keeping them because they are a "big engine" sounds like your main concern is the image you project while driving?

Personally I see no point in taking them off.

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2006 X5 Sport 4.4i