I have an AKRA EVO on my E90. The slips on's are specific. If you purchased slip ons for an E90, the bevelled ends of the pipes that would meet your x-pipe will be adjustable and in your kit will be 2 adapters you'd slip into the end of the pipe (you'd actually have two clamps about 2-3 inches apart holding the pipes to the adapters, and then to the x-pipe). E92/93 are the same length and will not come with adjustable adapters to meet the x-pipe.
2010 E90 ALPINE WHITE DCT/ MS STAGE II/ MS UNDER DRIVE PULLEY KIT/ KW SLEEVE KIT/ AKRA EVO/ ROHANNA RC-10 20's MATTE BLACK/ VERTICE FRONT BUMPER/ ARKYM CF DIFFUSER/ 15% TINT