While I have not examined the code on the MKW game disc, I have played long enough to get a good idea on what the rating system is. From what I can tell, this rating system is nothing like the MKDS point system. The only reason people think the 2 are similar is because some random person posted an MKDS rating chart on a GameSpot forum, back when MKW was less than a week old. So please, stop thinking about the MKDS rating criteria, MKW is a SEPARATE GAME.

From my experience (I have created more than 4 triple star licenses), the ranking criteria is broken into 2 parts:

50cc - Make sure you do not hit too many environmental hazards, fall off too often or drive offroad for too long, because all 3 of those directly influence your rank in 50cc! I have had triple star runs with like 3 blue shells a race, 57 points, etc (in 50cc). I compared them to my 60-point, 90% first place triple star runs (in 50cc). They all had the same thing in common: I never fell off or got hit by stuff like chain chomps, crushing ceilings and lava balls.

100cc, 150cc, mirror - Forget about not messing up, as it does not directly influence the ranking like in 50cc. Only two things matter: get 60 points and STAY FIRST. There is a magic percentage for each of the modes, if you do not stay first at least that percentage of the time you will not get a triple star.

Take this as you will, I have played Grand Prix extensively, and from my experience those are the only factors. The reason people think things like falling off in 100cc/150cc/mirror deduct from ranking is because falling off is an indirect influence. What I mean by that is that, while such mistakes do not themselves deduct rank, they can (and usually do) result in the CPU passing you, reducing the % of time you stayed first. I have had plenty of 100cc/150cc/mirror games where I fell off/got hit multiple times at each stage but got the triple star, just because the CPU was still unable to catch up.

I did find one exception to these rules: off-road. I've been experimenting with the Magikruiser in 150cc/mirror Banana Cup and I've noticed that going off-road for too long (without a speed-boosting item) deducts from rank even in mirror. From what I've observed so far, it doesn't deduct much at all and how much it deducts depends on how strong the off-road is (how much it slows you down by). For example, taking the shortcut more than once in Delfino Square without a shroom can deduct a whole star, compared to me having to stay in the blue water in Shy Guy Beach over 50% of the time to produce the same result.

You may be wondering, just how good do you have to be to stay 1st almost all the time, especially in 150cc/mirror? What does it take? Well, before I delve into some of the technical things about manual, I would like to point to DuVal AK47's video thread. That is approximately the level of play you should be at if you expect to get triple star ranks in 150cc/mirror.

You should know every track by heart and there shouldn't be a single track where you do not race well. You should know where to drift, where to mini turbo, where to wheelie, where to trick. On any given map, you should be able to get a large enough lead on the CPU to account for at least 1-2 blue shells. There is almost no room for mistakes. Be strong, be perfect, have your twitch ready. Be in the middle of a mini turbo or a wheelie as often as possible, while still taking the shortest paths.

Also, be aware that there IS something you can do about the blue/red shells you get spammed with. If you are using a high-speed, low-acceleration vehicle, instead of reaccelerating back up, stay where you are and mini-turbo from standstill. While it at first looks like you are wasting time just standing there, it saves you time in the long run, because a mini-turbo gets you to your top speed instantly. It reduces the time lost from a blue shell hit (or any hit that launches you) by about 1/3rd, if not more.

Having said that, mirror mode WILL make you fail a few times, regardless of how good you are, so be patient as well. Keep in mind that the CPU's only strength is their item usage. They fail at proper racing and situational awareness.

In conclusion, getting a triple star next to your name (NOT by using the cop-out "I'm going to race automatic and keep trying till I get it" method) is not an easy task and will take skill (lots of it), patience and usually lots of tries (the first time around anyway).

I tended to get 3-star ratings more often when I was really aggressive with hitting other players with items, in addition to the criteria you're already meeting.

Hidden Points are based on how well you perform in each race and are awarded as follows:

Positive Hidden Point actions:

~Total time for each race~
each race has a time which if you beat, will award you Hidden points. The faster you beat the time, the more points you receive

~Lead time~
the longer you stay in 1st the more Hidden points you will get

~Rocket boost/start~
you get 25 Hidden points for each successful rocket boost

~Mini-turbo~
you get 2 Hidden points for each successful mini-turbo

~Item attack~
each successful attack with an item will reward you 5 Hidden points

~Tricks~
each trick you perform will give you Hidden points as well

~Wheelies~
each successful wheelie will give you Hidden points

Negative Hidden Point actions:

~Off-track time~
Hidden points are deducted for time you spend off the track, you lose more Hidden points the longer you spend off the track. Exceptions are when you are under the effects of a star, mushroom, bullet bill or golden mushroom item

~Hit a wall~
you lose 20 Hidden points everytime you hit a wall

~Hit an obstacle~
everytime you hit an obstacle on a course (car, fireball, goomba, chain chomp, etc) you lose 30 Hidden points

~Fall off track/Get picked up by Lakitu~
you lose 70 Hidden points everytime you fall of the track or get picked up by Lakitu

Now for the Ranking System, which you can find below.

Key: CP = Championship Points
HP = Hidden Points

~ 60 CP: ~
1000+ HP = 3-star (***)
700 – 999 HP = 2-star (**)
400 – 699 HP = 1-star (*)
200 – 399 HP = A
0 – 199 HP = B
negative HP = C

~ 52-59 CP: ~
1000+ HP = 2-star (**)
700 – 999 HP = 1-star (*)
400 – 699 HP = A
200 – 399 HP = B
0 – 199 HP = C
negative HP = D

~ 47-51CP: ~
1000+ HP = 1-star (*)
700 – 999 HP = A
400 – 699 HP = B
200 – 399 HP = C
0 – 199 HP = D
negative HP = E

~ 40-46CP: ~
1000+ HP = A
700 – 999 HP = B
400 – 699 HP = C
200 – 399 HP = D
less than 200 HP = E

~ 0-39CP: ~
1000+ HP = B
700 – 999 HP = C
400 – 699 HP = D
less than 400 HP = E

As you can see from the tables above, you have to have an absolultly superb 4 races to get a triple star rank, but the double star and single star ranks are a little easier to obtain, but still relatively hard compared to the A and B ranks.

The star ranks do unlock a few things in the game which include:
Baby Daisy- Get a one star ranking on all 50cc Wii cups
Bowser Jr.- Get a one star ranking on all 100cc Retro cups
Dry Bowser- Get a one star ranking on all 150cc Wii cups
Rosalina- Get a one star ranking on all Mirror Wii cups
Cheep Charger- Get a one star ranking on all 50cc Retro cups
Jetsetter/Aero Glider- Get a one star ranking on all 150cc Retro cups
Sneakster/Nitrocycle- get a one star ranking on all 100cc Wii cups

But the main reason you want to get star ranks is for bragging rights and to show off, as if you get a:
single star rank or better on every single cup you’ll get a single star next to your name on Wifi
double star rank or better on every single cup you’ll get a double star next to your name on Wifi
or triple star rank on every single cup you’ll get a triple star next to your name on Wifi