Here's what I thought of:
HUD:
-Like Split Second and the WWE games starting with vs. RAW 2010, have the HUD items (time, rank, position, etc.) below the car (and the back view), moving with it, and delete the extra clutter on the upper left and right hand corners of the screen and relegate it where as explained above. If in the dashboard view, have it like Need for Speed: Shift where the driver list, position and time look like they're on both sides of the player's view.
-When you get disqualified during a license test or a special event, have the HUD animate like the Super Smash Bros. series of games when a player character is knocked off the field (falling down, etc.) when not using the dashboard cam. If possible, have the player choose which animations to use when something unfortunate like this happens.
-When disqualified in dashboard view by way of hitting walls and other cars, have the HUD animate while giving the player a motion blur as in Shift 1 - and have the motion blur match the severity of the hit.
-When a time is of bronze, silver or gold, have the player's time that shaded color the minute they cross the finish line. This is then followed by the colored trophy jingle as soon as the time is colored in.
-Give the player the option where to freely place the HUD.
Menu:
-Have the player select which menu sound effects to use (GT1, 2, 3, 4 - or remixed versions) or the default.
-Keep the custom soundtrack options, as always, but allow the player to customize the jingles (finish, disqualification, license prize, etc.) as well.
Gameplay - Flags:
-Have the player choose the size for black flag penalties (not license tests): Time Penalty (Mild), Forced Pit Entry (Strong) or Game Over (Severe). 'Game Over' immediately stops your car, starts it back up again under low power, gives the FINISH screen and results - and automatically drops you to last place - if you do not follow directions to go to the pits within the allotted time, indicated by a timer.
Depending on the severity of the unsportsmanlike behavior in 'Game Over' mode, either allow the player to have his/her prize winnings cut in half or award lesser prize winnings. If the leveling up for A-spec or B-spec is still there, award less experience.
If in a Championship Race in GT Mode, depending on the severity of the race behavior, 5 points should be deducted for cutting corners or a clear wall hit while 10 points should be deducted for a clear hit on other cars or spinning them out, while in 'Game Over', 20 points should be deducted for a disqualification. This can really affect positions if one is not careful.
-If this is the player's first time playing, introduce a tutorial that teaches them what to do when a certain colored flag (yellow, red, all types of blue, black, etc.) is waved (if all flags are confirmed to be in the game), and have the player attempt to follow directions in the tutorial. Depending on how well they do, they should be awarded a Gold, Silver, or Bronze prize.
Gameplay - General
-Have the player choose the scoring method upon finishing a race, Normal or Grade. Grade acts like another Polyphony Digital game, Omega Boost that tallies your grade up to 100 upon completing a level, and have points deducted for hitting walls or other cars or leaving the course or cutting corners (A-spec and B-spec) when the player finishes a race. You could receive a free car ticket if, for example, you score a 100 in five races. The score gets two zeros added to your prize winnings for this bonus. For example, if you score 95 points, you get 9,500 credits extra added on to the prize winnings for the normal race.
As a director, you can also be graded on your gameplay/performance in this mode.
Depending on the severity of any unsportsmanlike behavior demonstrated by the player, up to 50 or all points should be deducted depending on the penalty settings as explained above.
-Keep all the options (including control) from GT5.
Gameplay - License tests/special events:
-Have the player choose the scoring method as explained above, but this time in Grade mode, have the player start off with 100 points for each test. For every mistake they make, 5 points should be deducted for a half-spin or a full-spin, 10 if they cut the track, 20 if they hit other cars, and an instant disqualification indicated by the loss of all points (Lose would be the default setting) if they hit a wall or leave the course. Also have the player choose how many points to deduct if these things happen, and the option to choose instant disqualification if a player makes contact with other cars.
Gold, Silver or Bronze times should be about 10-20 points toward your final grade of a challenge and can be adjusted by the player. So, for example, if a player finishes with 60 points and gets a Silver time, the final grade would gradually increase. You would need a score of 70 points (which can also be changed freely (70-77 or higher)) to successfully clear the test/challenge. No extra points are awarded if the time is exceeded, but you could easily get a Bronze prize if you don't make too many mistakes, for example.
-In Grade mode, have the player receive extra credit if, for example, in the final exam of a specific license, he or she goes 1 lap without touching any cars, hitting walls, leaving the course or cutting the track. Also come up with extra credit challenges during license tests. There should be a PSN trophy if a player does at least 5 of them without being disqualified.
That's all I could think of right now...