Car Modifications
This car started its life as a totaled Z3M – which was rebuilt only to find that the salvage title would make it extremely difficult to register for street driving even though it was primarily intended to be a track car.  I subsequently purchased a clean 1.9L from FL that was having EWS issues that made it undrivable but fit my needs well.  I purchased the 1.9L, and completely swapped the Z3M entirely to the 1.9L chassis.  As a result, the only non-Z3M component you’ll see throughout the entire car is the trunk floor doesn’t have a centered battery compartment.  Otherwise, from all other perspectives aside from a VIN search, this car is a Z3M but obviously not for resale – that was never my intent, so know it isn’t one for pricing.  Given the level of modification, I would not expect this to be a traditional Z3M sale anyway.
From the exterior, this car looks mostly stock until you hear it.  Inside however is a very different view and if driven, the setup is all track focused. Below are key modifications and I’m sure there are others I’m missing.   I have several parts that will come with the car should it sell at a reasonable price, which would include a Euro ITB adapter, TBs, and intake plenum, all of the parts I removed that could potentially be reused, a rear bumper, trunk lid, and a few other miscellaneous items.

Engine
• M50 Intake
• Custom fabricated airbox for 3.5” tubing to MAF w/AFM filter insert
• 3.5” Porsche MAF with silicon intake to TB
• Nuke Fuel Rail w/SS braided lines to/from filters and hard-lines
• Pink Top Injectors
• Performance Coils
• Custom Oil Catch Can
• SAP Delete
• HVAC coolant bypass (HVAC delete)
• CSF Increased capacity radiator
• Custom overflow tank
• All silicon coolant hoses
• SS solid engine mounts
• Oil coolant adapter/spacer at filter housing (between block and housing, not a filter cap style)
• Oil thermostat and cooler system
• Front subframe reinforcement for engine mounts
• Aeroquip adjustable FPR with gauge port
• Electric coolant fan (manual activation)
• Turner Motorsports pulley setup
• Power steering delete w/custom serpentine belts

Exhaust
• SS Shorty headers
• Supersprint resonator mid-section (catless)
• Magnaflow custom exhaust mid-to-rear

Drivetrain
• SS Solid transmission mounts
• Z3M differential ratio/housing/cover
• Stock diff bushing
• Bimmerworld solid chassis mount race shifter
• Subframe reinforcements welded in for diff mounting
• JB Racing flywheel w/M5 clutch-masters pressure plate/disk

Suspension
• BC racing coilovers w/spare springs
• BC racing front camber plates
• Solid AKG control arm spherical bearing style bushings
• Bimmerworld solid spherical CA to spindle bushings
• Rear adjustable camber/caster tabs
• Delrin rear TA bushings
• Bimmerworld SS Solid Subframe mounts
• AKG solid steering bushing
• Rear subframe reinforcements for sway bars
• ACS delete

Brakes
• Dual MC setup w/Wilwood MC’s
• SS lines and replaced SS hard lines to MCs
• Custom MC bracket with balance bar
• Wilwood front/rear calipers (and Porsche 996 setup available)
• Custom fluid reservoirs (no fluid level sensors)
• ABS delete

Interior Safety
• HardDog track bar – welded in with custom harness bar
• 2-nozzle trunk mounted fire suppression system (both pointed at driver)
• 6-point harnesses compatible brackets and mounting
• Planted side–mount seat bracket w/VAC motorsport floor mounts (as low as you can possible get)
• Bimarco FIA Futuro race seat w/custom “M” logo
• NASA/SCCA compliant kill switch
• Fire rated door cards w/custom pull latch release
• Engine bay heat shield firewall wrap (high quality aluminum/fiberglass cloth)
• Quick release steering hub
• Momo 350mm steering wheel

Interior Monitoring
• Custom center console (oil pressure, oil temp, water temp)
• Dash mounted shift monitor
• Oil temp, pressure, and coolant temp warning lights based on custom settings linked to gauges (can be set by user)
• Original gauge cluster, modified to avoid SRS warning lights

Exterior Modifications
• Exterior triggers for both fire and electrical kill switch
• Bumper grills replaced with aluminum mesh
• Fire suppression trigger is mounted in radio antenna hole
• Electrical kill switch pull cable mounted thru cowl cover
• 2 Sets of original M-style wheels (street tires mounted and Azenis 615+ for track)
• New soft-top installed
• High quality hood pins installed (solid SS components) with original hood latch retained for safety reasons
• Bimmerworld front/rear tow straps mounted to bumper mounts

Other Work
• Fully gutted engine bay and interior w/respray
• Steering column spaced to reduce height
• Relocated wiper fluid and tank (much smaller in size for track use only)
• Custom electrical switches installed to avoid issues with stock harness modifications
• HVAC removal with electric defogging fan/ducting
• Gauge center console includes gauges for – oil temp, oil pressure, water temp, and voltage.
• Center console includes: switches to control gauge activation, gauge warning light system, hvac blower, and cooling fan (radiator), ignition activation, push button start, relocated window switches, and hazard lights.

A multi-year build process is located on the GRM forum site - https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/1998-bmw-m-roadster-hpde-project/88267/page1/

Sadly I started the build almost a decade ago, ran it for only 2 years before realizing I need to sell to make room for my dedicated race car.