The M135i isn't a successor to the 135is - they didn't make an Exx hatchback with the N54/N55 in the UK/Europe.
It's a different car completely!
Pretty respectable time IMHO.
Current: F21 M135i
2015 F31 330dX, 2011 F20 120d SE , E90 335i, 2010 Alpine White N55 135i 6MT, 2009 LMB LCI N54 135i - Cobb tuned!, 2010 F10 530d SE, 1986 E30 318i,1981 E21 320i Auto