Slightly Mad Studios has rolled out Project CARS free major patch 4.0 on PS4 and PC adding new features as well as bug fixes ahead of the game's DLC releases in the following months.   

Posted on the game developer's official forum is the full list of Project CARS patch 4.0 notes which is first made available for PS4 and PC while the update is still coming soon for Xbox One users.

Below is the summary of the new and enhanced features:

New & Enhanced Features 

• Online - added support for 'Force Default Setups' in Multiplayer restrictions screen.
• Online - players driving the wrong way will now have their collision disabled and their vehicles will display as ghost cars.
• Online - lobby search settings are now saved between sessions.
• Career - mandatory pitstop opening lap will now scale when the player scales the length of the race. For example, if the race was set to 5 laps, the pits would open for
  the mandatory stop on lap 2. If the player now scales the race length to 15 laps, the pits will open on lap 6 for the mandatory pitstop.
• HUD - when adjusting real-time settings, for example Brake Balance, the player will now see a HUD message to indicate what the setting has been changed to. The HUD will display "N/A" in the real-time settings HUD, messaging when a specific setting is not available due to it being disabled in MP session or not present on the vehicle.
• GUI - added a game version number display to the main menu.
• Assists - Enhanced Brake Assistance system so that people who are unable to use
  brake controllers at all can still play the game with this assist enabled.
• Assists - the Best Line assist now provides an option to only show the braking areas
• Tracks - Movable trackside objects and broken-off car parts will now be removed from the track after impacts.

Online

• New - added support for 'Force Default Setups' in Multiplayer restrictions screen.
• New - players driving the wrong way will now have their collision disabled and their vehicles will display as ghost cars.
• New - lobby search settings are now saved between sessions.
• Fixed an issue where the AI could remain stuck on the grid after the previous host left the session.
• Fixed an issue where the player was unable to select the Bentley GT3 in online races.
• Fixed an issue in Create Lobby where selecting Vehicle 'view details' would reset the class filter.
• Fixed an issue where the in-game chat box would scroll when the player pressed the accelerator and brake controls.
• Various tweaks to the behaviour of cars that are terminally damaged, and cars will no longer try to teleport to the garage if there are no pit lanes.
• Fixed an issue where the player could drive out of the garage again after retiring from a race.
• Further tweaks and improvements to the online lobby Car Class GUI - classes are now sorted alphabetically; changes are now only apply once the player accepts the new settings; 'Create' options defaults to 'Any' class; fixes an issue where the host would see only one vehicle in the quick vehicle chooser list if identical vehicles was
  set to 'yes'.
• Fixed the rolling start option so that toggling the rolling start flag correctly updates MP game data.

GUI, HUD, Telemetry

• New - when adjusting real-time settings, for example Brake Balance, the player will now see a HUD message to indicate what the setting has been changed to. The HUD will display "N/A" in the real-time settings HUD messaging when a specific setting is not available due to it being disabled in MP session or not present on the vehicle.
• New - added a game version number display to the main menu.
• New - the Best Line assist now provides an option to only show the braking areas.
• Rebalanced the point at which Forecast weather becomes Current weather in the UI display so that the info display changeover better matches what the player is seeing in-game.
• Track temperature is now displayed on all in-game menus.
• Fixed an issue where the Time Progression slider skipped every 2nd option when moving the slider left or right.
• Track temperature will now display correctly based on the unit system and language selected by the player.
• Fixed an issue where the tyre wear meters on the HUD telemetry screen were flipped for the right front and left rear tyres.
• Track Temperature and Weather information are now positioned uniformly across all in-game screens.
• Removed redundant leading zeros from the KERS motec display.
• Fixed an issue where accessing the map or telemetry in the monitor screen would disable the player HUD in game.
• Enabled scrolling of the drivers list on the post race Standings screen.
• Vehicle Class icons - updated vintage F1 and vintage GT class icons.
• New GUI image with real-world livery for Ford Capri Group5.
• Fixed an issue where the menu borders would at times display unintended colors.

General

• New - movable trackside objects and broken-off car parts will now be removed from the track after impacts.
• Enhanced Brake Assistance system so that people who are unable to use brake controllers at all can still play the game with this assist enabled.
• Reworked the stretched headlight reflections to be more accurate to real life.
• Fixed an issue where the Driving Line assist would become invisible when particles were set to off.
• Ensure that players cannot turn on assists using hotkeys in community events, when the assists have been explicitly disabled for the event in question.
• Fix further cases where the pre-race cameras would at times cut into the track surface.
• Fixed an issue where vehicle windows would at times not render correctly when using centre cockpit cam and helmet cam.
• Tweaks to gamma settings to closer match the PC and Xbox One platforms.
• Fixed a potential crash when returning from in-game to main menu.
• Fixed an issue with the rendering of shadow edges, improving overall shadow rendering.
• Improved general game stability.

According to PlayStation Lifestyle, through its On Demand Program, Slightly Mad Studios will be able to continue to release free game updates intended to remedy bug and issues experienced by the gaming community, improve balancing, expand game's features, and other additions .

Moreover, Slightly Mad Studios has also announced its plans of future DLCs that racing fans can expect from the game. The developer revealed that a new Track Expansion will be launched soon and a "special fan-requested Car Pack" will arrive in October.

"And our ON DEMAND program has only just started! With another Track Expansion coming soon, a special fan-requested Car Pack in October, and then another huge Track Expansion coming in November, Project CARS will continue to remain current and reflective of player feedback well into the future," Slightly Mad stated. 

Other than the game's upcoming expansion packs, Slightly Mad had already confirmed earlier that Project CARS 2 is in development and will feature a Co-Op Career Mode and include the largest track roster ever when it releases on Xbox One, PS4, and PC.