With the greatest of respect I think some folks are being somewhat lenient on Hyundai here. There should be no requirement whatsoever to start changing bits on brand new cars that cost £30K just to get the gearbox working properly, or taking comfort in the fact the problem is 'only when cold' or 'only when going into a certain gear'.
I've owned a lot of sporty cars over the years and I've never had a car that's had an issue like this with the gearbox. (And come to think of it, I've never owned a non-sporty car that's had an issue like this either.)
Even when it's working properly it's not the best gearbox in the world (good, but not great*), so when mine flat out refuses to go into sixth completely at random, it really gets on my nerves.
The fact there's a TSB proves Hyundai know about it, so why are they leaving us at the mercy of an incredibly inconsistent dealer chain and make us 'prove' that our car has the problem?
Way to burn customer goodwill guys.....
Don't get me wrong, I really like my i30N, but this gearbox crap is starting to negatively colour my opinion of the car.
* FK2 Civic Type-R, now that was a great gearbox. I only changed from that because it was sorely lacking a comfort mode (which of course the i30N has).