(From what I understand its supposed to be level based, but I really have no idea because these matches have no rhyme or reason )
But, this is part of the problem, actually.
People don't understand how MPR should work.
Character level shouldn't matter. Simply because the following amplifiers exist: Character star levels. Crew members. Crew member star levels.
This one statement alone will prove my point:
If I have a 5 star character at level 20, with a fully decked out crew, I'm going to ransack every other 2 star level 20-25 on the track.
I in fact did this. I whaled out on the frozen boxes early on, and had a 5 star Anna with mostly 3-4 star crew. Based on sheer stats alone, I could just drive around the track and beat everyone else, at level 20-25 without trying. If I left her at 20, I'd be a significant problem for everyone at that level.
I have another problem with level based match making, because I have a level 41 Captain Gantu, that I can not get out of the 16-20 MPR range, because based on my level I'm playing against high diamonds, champs, and people fighting for grand champ. If I have to play like I'm fighting for Grand Champ to get out of Emerald, I'm just simply not going to ever get out of that MPR range, which is crazy.
Level based matchmaking is a very bad way to matchmake.
MPR should matter. MPR should be the game's way of sorting the strength of players.
Does this mean, if I have a level 40 character I've never played, that it will be playing against low level characters? Yes.
Does this mean, if I have a level 40 character I've never played, that it will move past playing against playing low level characters, and those with less skill quickly? Also, yes.
Does this mean, if I have a 2 star level 20 character with low level crew, then I will occasionally get beat very, very badly by someone climbing on a higher level or better equipped character? Also, yes. But keep in mind, that will only happen occasionally while people are gaining ranks on their higher level/well equipped characters.
Does this mean, if I have a 5 star level 20 character with maxed crew, then I will be playing against higher level characters,
Your overall gameplay would be better, and you'd be regularly matched with equally skilled and/or equally equipped opponents, with similar stat levels
MPR based matchmaking would smooth out how rough the lobbies are, and it would do it quickly.
If you have a level 40 character, assuming you also have the skill level necessary to climb the MPR ladder, you should be able to breeze through the early ranks, where the skill levels and character levels are low.
If you have a level 40 character, assuming you DO NOT have the skill level necessary to climb the MPR ladder, you should be able to play with equally skilled players, that balance with your character's stats. Yes, that means you might be playing against some level 30s, but they would have a reasonable match with you, because you aren't good at the game.
...and as a caveat...
If you love the game, and you're bad at it, but you have a level 40 character, you shouldn't be forced into matches with other level 40s that are fighting for grand champ.
If you're an Emerald player, you should be able to enjoy a match with other Emerald players.
If you're a Diamond player, you should be able to enjoy a match with other Diamond players.
If you're sweating for Grand/Ultimate champ, you should be able to play against other sweaty Grand/Ultimate champ players.
It is not reasonable to have matchmade lobbies that consist of Emerald players and Champion players.
It is not fun for the Emerald players to get wrecked with no hope of ever reaching a higher rank, because they're consistently getting paired with people who are better than they are, based on their character's level, and not their skill level.