I've got about 6500 miles on my car.
Broke it in like a granny for the first 1500.
I drove it hard a few times during break-in just for $hits and giggles.

Since break in, i've missed gears 3 times. Let the clutch out too fast and just missed it. Felt like i grinded it but it never went into gear.

How bad is this? I know it's not good. But just how bad?

| 2004 G35 Coupe 6MT | Diamond Graphite/Graphite | Premium Pkg | Aero Pkg | Navigation | SKYLINE+GT350 emblems | Clear Corners | 35% & 50% Tints |

 

It's not that bad at all. It's not the gears of the transmission itself that is grinding when you do that. Those stay in contact all the time. There are dog gears which lock the shaft to the actual gears themselves. The dog gears are much stronger and make contact at several points instead of just one point. They can take quite a bit of abuse and wear before even signs of wear will be noticed. The occasional missed shift shouldn't be anything to really be concerned with.

 

Sure as hell sounds bad. Feels horrible too. RPMs reved all the way to red line, too. :\

| 2004 G35 Coupe 6MT | Diamond Graphite/Graphite | Premium Pkg | Aero Pkg | Navigation | SKYLINE+GT350 emblems | Clear Corners | 35% & 50% Tints |