When engine/gearbox are cold (say 11c) and I engage the clutch on idle in neutral, I hear a bearing noise/whine from the gearbox. Goes completely after driving 3 or 4 miles. Normal I presume?
In general the gearbox can resist going into first sometimes too, but this seems it can be typical of these gearboxes.
Have you checked the levels in gearbox and diff?
I read somewhere that Mazda went quite Scrooge on the levels they added , putting in the minimum .
As a 23 plate I’d be taking it to Mazda and demanding they sort it…… you are not alone in having this problem
Yes it’s still under warranty. Mazda dealers charge £190 investigation charge if they can’t find a fault. May have to wait 10 months for a service to avoid this. Unless I can get them just to check the levels…
If the noise is a whirring when in neutral and idle, which goes when you put the clutch in, returns when you take you foot off the clutch pedal, mine (an ND) has had that since I had it (I think ) and I’ve even sat in some other people’s NDs when out and about, and all but one have done it too. There was even a TSB for it, but that was for the NC. Quite a bit on this on the US forum. Outcomes ranging from it’s fine, to the sky’s falling in etc.
With regard to some resistance into first, mine did that for a good 5-6K miles, some times at traffic lights etc. It loosed up more and, touch wood, haven’t done that pretty much since. Ditto 1st to 2nd was a bit harder when the car was sub 5K miles or so, but again, fine now. Maybe I just got better at knowing the car.
Thanks, yes that’s what I experience. Mine still just under 3k miles and just under 2 years warranty left so will live with it for a while longer methinks. Just with all the rhetoric about its ‘near perfect’ box it’s easy to then expect perfection…
FWIW, my 1.4 Audi A3’s gearbox offers easier changes at the moment, and still feels tight, but it does have 54k miles on it…
A customer of mine had the same issue at a similar mileage and Mazda told him his gearbox was fine, they also said IF we change it it could be worse…… FFS
However he stood his ground and made them fit a new gearbox and now it’s fine.
Mazda unlike some other manufacturer’s I’ve dealt with are terrible at customer service
Mention it to mazda service department as if something happens outside of the warranty period and its on record that you informed them of this and something happened (god forbid) due to their inadequate response, then you can say “sort it as i told you so”.
But what is wrong with his gearbox?
He’s done sub 3K miles so it’s still bedding in, so might have a little resistance from 1st to 2nd when cold, and putting it into first. Mine did exactly that at that mileage and now those things have totally gone. Should I have had a new box’ too? 
And the whirring at idle, mine has done that from the get go, and is exactly the same 6 years on, and I don’t know how many people in Tesco car parks thought I was a loon asking them to sit in their car and see if their’s did it- after reading the internet advice that the sky was about to fall in etc . Ditto if you go on the Miata forum, shed loads got that too and to the best of my knowledge, none have gotten any worse. The same wirring at idle ‘issue’ was TSB’d on the NC as well,saying it;s basically nothing. Do I still need a new gearbox as well 
If you are happy with yours that’s absolutely fine and I’m pleased for you…
But who knows if the OP’s is louder than yours??
Personally I’ve seen a few that are unacceptably noisy and I have the offending item on my desk at work…… it’s a relatively cheap bearing that Mazda put in.
I still have 2yrs warranty left so will relax. I don’t think it’s that noisy. Just something I noticed. Comforted by the fact it goes away after driving 3 or so miles.
Thanks for the replies.