Class
Modification	Stock (128i/135i = DS, 1M = AS)	Street Touring (128i = STX, 135i = STU)	Street Prepared (128i/135i = ASP)	Street Modified (SM)
Suspension:
Springs
Shocks	Max of 2 external damping adjustments, no electronic controls, +/- 1" length of OEM fully extended
Anti-roll (sway) bars	Front or rear, but not both
Strut tower bars
Adjustable Camber Plates
Alignment pin removal mod
Slot upper shock tower holes	*
Upgraded Bushings	For upgraded sway bar only	Non-metal	Non-metal
M3 Lower Control Arms		(or camber plates / slotting upper tower holes, not both)	(or camber plates / slotting upper tower holes, not both)
Coil-overs (KW, AST, TCK, etc.)
BMW Performance Suspension (full kit)
Dinan Stage 1 Suspension (kit)
Dinan Stage 2 Suspension (kit)
Dinan Stage 3 Suspension (kit)
Brakes:	DS/AS	STX/STU	ASP	SM
Upgraded pads
Upgraded fluid
Upgraded discs (rotors)		Any equal or larger, must be metal	Any equal or larger, must be metal	Metal
Upgraded calipers		Piston count equal or more	Piston count equal or more
Stainless-steel lines		DOT approved
Brake ducts
Speed bleeders
Disable ABS
BMW Performance Sport Brakes (kit)
Dinan/Brembo Front and Rear Brakes (kit)		If these bolt to standard location without adapters (?)
Wheels/Tires:	DS/AS	STX/STU	ASP	SM
Wheels	Stock size, +/- .25" offset
Tires	Measurable tread, fit within fenderwell	285mm max, 140 wear rating min
Spacers	Resulting offset = +/- .25" stock
Fender lip rolling
Wheel studs
Engine:	DS/AS	STX/STU	ASP	SM
Spark plugs/wires/coil
Air cleaner element
Oil filter
Thermostat
Oil cooler upgrade
Silicone Hoses		**	**
Intercooler upgrade
Water Injection
ECU flash/replace (BMW PPK, JB3, Dinan, Proceed, etc.)		***
Tunes (SSTT, JB+, etc.)
Air intake
Exhaust (rear-section - ex: BMW Performance)
Exhaust (mid-pipe - ex: N54 to N55 mid-pipe conversion)	2011+ (N55) models only	Any emissions legal
Exhaust (manifold)		Any emissions legal
Exhaust (downpipe - ex: cp-e)		Any emissions legal
Catalytic Convertor replace/remove		Replace only - Any cat(s) allowed, must attach within 6" of OEM
Turbo upgrade
Boost controller
Turbo Timer
Blow-off valve
Compressor bypass valve
Transmission:	DS/AS	STX/STU	ASP	SM
Clutch
Flywheel
Limited Slip Differential
Clutch Delay Valve Mod
Interior:	DS/AS	STX/STU	ASP	SM
Seat replacement		25 lbs min, stock mounts, top higher than head center, fully upholstered	Fully upholstered, full back with headrest	Fully upholstered, full back with headrest
Rear-seat removal
Short-throw shifter
Shift knob/boot
Custom pedals
Steering Wheel (BMW Performance, MOMO, Nardi, etc.)
Safety Harness	Seats may not be cut for installation. Existing restraints cannot be removed.	See stock	Standard seat-belts may be removed to facilitate alternative restraints
Harness Bar	Two bolted attachment points, or 'C'-type with four bolted attachment points	See stock	See stock. 6-8 point roll-cages are also allowed.
Airbag			Can be disabled	Can be removed
Exterior:	DS/AS	STX/STU	ASP	SM
Body kit	? (13.2)	? (14.2F)	? (13.2)
BMW Performance Spoiler	? (13.2)
Replacement Kidney Grills
Replacement mirrors
Replacement side skirts	? (13.2)	? (14.2F)
Replacement Rear diffuser	? (13.2)		? (13.2)
Replacement hood
Tow hook
Trailer hitch
Debadge
Other:	DS/AS	STX/STU	ASP	SM
Disable DTC/DSC
Remove radio/speakers/wiring			Must leave wiring, speaker holes must be covered
Weld sunroof			****
AC removal
Battery replacement		Same voltage	Same voltage	Same voltage
Emissions removal
Fuel cell			+/- 20%, same location	5+ gallons
Minimum weight	None	None	None	2400 lbs.

* 13.8E - Allowed provided it is an authorized modification by the manufacturer.
** 13.10J - Must be the same size/shape/location/stiffness/contour/internal wall texture as OEM
*** Flash/replacements are allowed provided they do not alter factory boost levels or traction control parameters. Even those which provide stock maps or "bypass" modes are not allowed; "Alternate software maps which violate these restrictions may not be present during competition, regardless of activation."
**** 15.2O - "Sunroof equipped cars may be converted to a solid-roof configuration provided a model without a sunroof is listed on the same line in Appendix A." - Does convertible count as a "model without a sunroof"?