The BMW X4 made waves at the 2013 Shanghai auto show earlier this year, but then it was only on concept guise.Spy photographs of the production version is out. The production-ready model will be revealed later this year before going on display at the 2014 Detroit auto show.Image galleryThe X4 will have only a few engine options, most likely in 35i and 28i guise with turbocharged two and three-litre engines. The spied images reveal only two exhaust pipes on one side which suggests this could be the 28i model. With that said, the 20d is important in the X4 range and it could be that model too. Interior images are yet to be seen, but we’re hoping it will have a lot more M Performance goodies.