OEM parts categories for 2018 Audi A4: A C Compressor (A C Compressor) | A/C & Heating (A/C & Heater Control Units, A/C Condenser, Compressor & Lines, A/C Evaporator Components, Air Conditioner, Automatic Temperature Controls, Blower Motor & Fan, Heater Core & Control Valve, HVAC Case, Switches & Sensors) | Air & Fuel Delivery (Air Intake, Cruise Control System, Fuel Injection, Fuel Supply, Fuel System Components, Intake Manifold, Intercooler, Throttle Body, Turbocharger) | Aperture Panel (Aperture Panel) | Balance Shafts (Balance Shafts) | Belts & Cooling (Belts & Pulleys, Cooling System, Radiator, Water Pump, Cooling Fan, Hoses, Lines & Pipes, Intercooler, Radiator & Components, Trans Oil Cooler, Water Pump) | Belts Pulleys Belts (Belts Pulleys Belts) | Blower Motor Fan (Blower Motor Fan) | Body & Hardware (Aperture Panel, Uniside, Back Glass, Bumper & Components - Rear, Center Pillar & Rocker, Cluster & Switches, Instrument Panel, Console, Cowl, Dash Panel Components, Ducts, Electrical Components - Front Bumper, Electrical Components - Rear Bumper, Fender & Components, Front Bumper, Front Door, Front Door - Glass & Hardware, Front Door - Lock & Hardware, Front Seat Components, Glove Box, Grille & Components, Hinge Pillar, Hood & Components, Information Labels, Inner Structure - Quarter Panel, Jack & Components, Outside Mirrors, Pillars, Rocker & Floor - Floor & Rails, Pillars, Rocker & Floor - Under Cover & Splash Shields, Quarter Panel - Glass & Hardware, Quarter Panel & Components, Radiator Support, Radiator Support - Splash Shields, Rear Body, Rear Body - Floor & Rails, Rear Body & Floor - Under Cover & Splash Shields, Rear Door, Rear Door - Glass & Hardware, Rear Door - Lock & Hardware, Rear Seat Components, Rear Spoiler, Roof & Components, Seat Belt, Sound System, Splash Shields, Structural Components & Rails, Sunroof, Trunk, Trunk Lid, Windshield Glass, Reveal Moldings, Wiper & Washer Components) | Brake Components (Brake Components) | Brakes (Anti-Lock Brakes, Brake Components, Front Brakes, Hydraulic System, Parking Brake, Rear Brakes) | Bulbs (Bulbs) | Bumper Components Front (Bumper Components Front) | Case Related Parts (Case Related Parts) | Charging & Starting (Alternator, Battery, Starter) | Cluster Switches (Cluster Switches) | Cooling Fan (Cooling Fan) | Cruise Control System (Cruise Control System) | Door Components (Door Components) | Driveline & Axles (Front Axle Shafts & Joints, Drive Axles) | Driver Seat Components (Driver Seat Components) | Electrical (ABS Components, Air Bag Components, Alarm System, Antenna & Radio, Anti-Theft Components, Communication System Components, Electrical Components, Front Door, Front Seat Belts, Fuel Door, Fuse & Relay, Heated Seats, Horn, Ignition Lock, Ignition System, Instruments & Gauges, Keyless Entry Components, Lane Departure Warning, Lumbar Control Seats, Mirrors, Navigation System, Parking Aid, Power Seats, Powertrain Control, Rear Door, Rear Seat Belts, Senders, Starter, Sunroof, Switches, Trunk, Wiper & Washer Components, Wiring Harness) | Emission Control & Exhaust (Emission Components, Exhaust Components, Exhaust Manifold, Heat Shields) | Emission System (Emission System) | Engine (Engine, Engine & Trans Mounting, Engine Appearance Cover, Engine Parts, Mounts, Cylinder Head & Valves, Camshaft & Timing, Oil Pan, Oil Pump, Balance Shafts, Crankshaft & Bearings, Pistons, Rings & Bearings, Transaxle Parts, Turbocharger, Valve & Timing Covers) | Engine Mounting (Engine Mounting) | Exterior Trim Pillars (Exterior Trim Pillars) | Exterior Trim Trunk (Exterior Trim Trunk) | Floor Rails (Floor Rails) | Front Axle (Front Axle) | Front Door (Front Door) | Front Suspension (Front Suspension) | Front Suspension Components (Front Suspension Components) | Fuel Door (Fuel Door) | Fuel System Components (Fuel System Components) | Glass Door (Glass Door) | Glass Hardware Back Glass (Glass Hardware Back Glass) | Glass Hardware Quarter Panel (Glass Hardware Quarter Panel) | Glass Windshield (Glass Windshield) | Headlamp Components (Headlamp Components) | Headlamp Washers Wipers (Headlamp Washers Wipers) | Headlights & Lighting (Backup Lamps, Headlamps, Headlamp Washers/Wipers, High Mount Lamps, License Lamps, Side Marker Lamps, Tail Lamps) | Heat Shields Emission (Heat Shields Emission) | Hood Components (Hood Components) | Hydraulic System Brakes (Hydraulic System Brakes) | Instrument Panel (Instrument Panel) | Instrument Panel Components (Instrument Panel Components) | Intercooler Air (Intercooler Air) | Interior & Exterior Trim (Exterior Trim - Fender, Exterior Trim - Front Door, Exterior Trim - Pillars, Rocker & Floor, Exterior Trim - Quarter Panel, Exterior Trim - Rear Door, Exterior Trim - Trunk Lid, Interior Trim - Front Door, Interior Trim - Pillars, Rocker & Floor, Interior Trim - Quarter Panels, Interior Trim - Rear Body, Interior Trim - Rear Door, Interior Trim - Roof, Interior Trim - Trunk Lid) | Interior Trim Pillars (Interior Trim Pillars) | Interior Trim Trunk (Interior Trim Trunk) | Lower Control Arm Rear (Lower Control Arm Rear) | Maintenance & Lubrication (Automatic Transmission, Belts & Pulleys, Filters) | Mirrors (Mirrors) | Oil Cooler Engine (Oil Cooler Engine) | Passenger Seat Components (Passenger Seat Components) | Powertrain Control (Powertrain Control) | Rear Door (Rear Door) | Rear Floor Rails (Rear Floor Rails) | Rear Suspension Components (Rear Suspension Components) | Seat Belt Body (Seat Belt Body) | Shocks Components (Shocks Components) | Stabilizer Bar Components (Stabilizer Bar Components) | Starter (Starter) | Steering (Shroud, Switches & Levers, Steering Column & Wheel, Steering Gear & Linkage) | Steering Column (Steering Column) | Steering Column Assembly (Steering Column Assembly) | Steering Gear Linkage Steering (Steering Gear Linkage Steering) | Steering Wheel Trim (Steering Wheel Trim) | Struts Components (Struts Components) | Sunroof (Sunroof) | Supplemental Restraint System (Supplemental Restraint System) | Suspension (Axle & Differential - Rear, Drive Axles - Front, Drive Axles - Rear, Drive Shaft - Rear, Front Suspension Components, Lower Control Arm, Stabilizer Bar, Rear Suspension Components, Lower Control Arm, Upper Control Arm, Stabilizer Bar, Shocks & Components - Rear, Stabilizer Bar & Components - Front, Struts & Components - Front, Suspension Mounting - Front, Suspension Mounting - Rear, Wheels) | Transmission (Automatic Transmission, Gear Shift Control - AT, Valve Body) | Trunk (Trunk) | Under Cover Splash Shields Body (Under Cover Splash Shields Body) | Wiper Washer Components (Wiper Washer Components)