All the signs are there but spouse won't accept it

My kiddo is almost like yours,  36mo but does laugh/smile, no hand flashing, but extreme feeding issues (only drinks milk, no solids).  His pediatrician said for us to use speech and food therapy and only after a few months she'll evaluate. If anything it may be mild. 

If you're wife isn't comfortable getting a diagnosis right now, ask to at least have your son see a speech therapist. That way he'll be able to make some progress vs letting things happen

Bi-lingual or not, elective mute or not, I would expect some really good and habitual indicators of comprehension and attempts to communicate by other means by two and a half. 

There are other possible explanations, and personally, I'd get them all checked out.  Can you have a chat with your health visitor on your own?  I've never raised an autistic child, but I'd have thought the professionals would want to eliminate other things; hearing, other developmental delays etc and at least put him on the radar for possible assessment for autism, if they haven't found another explanation.

Actually, even though you are saying there don't appear to be sensory issues at present, I'd keep an eye out and take care anyway.  They can suddenly 'switch on'.  I'd eat anything until I went to school, it was after my first school lunch that most things that went in my mouth smelt or felt bad.  My sense of pain can be either very intense out of all proportion to the cause, or non-existent when I ought to be rolling on the floor in agony.

At just 30 months old he's still very young for a diagnosis, if he is autistic. Being a boy he has an advantage, as they get diagnosed earlier (and far more easily, usually) than girls, but it's still difficult at such a young age. Much of what you're describe could be attributed to other things, so until he's a bit older and there's more to go on, you might struggle to get a diagnosis. It's a bit of a lottery, to be honest. We struggled for years to get help for my granddaughter who we knew was autistic, but it wasn't until the age of 9 that she was finally diagnosed. At age 3, CAMHS told us she was too young to diagnose, and to come back when she was 5. I agree that the sooner the diagnosis, the better, so you could always try. Does your son attend a nursery or child care of any description? If so you could speak to someone there to see if they've noticed anything. And there's nothing to stop you going to see your GP on your own to get his advice and guidance. Getting your wife to accept that he may be autistic is a whole other problem but I'd see what the next step would be before trying to tackle that one!

Sometimes he does do that, but only if i really (REALLY!) try, and repeat the request over and over over....

He does seem to count (not "one-two-three", but rather "oua-tooo-tiii", but you can tell what he means), or say some letters and shapes (again in his own "language).

I'm a linguist and have studied child language acquisition.  Bi-lingual children can be a little delayed in producing their first words, but usually then catch up quick.  Some neurotypical children say nothing for a couple of years, but skip the usual early stages of development and jump straight in with whole sentences later.  They understood but didn't feel like trying yet.  Your child should nonetheless be showing signs of language comprehension.  Passing you teddy if you ask for it, even if he can't or does not want to say "teddy" yet.  Will he do that?

In your shoes, yes, I would want this checking out because of the absence of interaction - laughing, eye contact and the lack of pointing.

Could it be that your other half is resistant because underneath she's scared there might be a problem?

The other thing to get checked out is his hearing, of course.  

From what you've described it does seem like denial like you said, I'm 22 I don't have kids but I do know that I wish someone picked up on my autism when I was young, I wouldn't have had such a hard time growing up, that might be worth explaining to her.

Also don't worry if he is autistic he's just different and might need help with certain things that won't come naturally like how they would for you or your wife.

Has there ever been a case of someone with autism/ADHD/ Bipolar in your family or hers? That can be a very good indicator because it is something that gets passed down genetically.

He is still very young so the impact on his life won't be high yet but has he gets older if he doesn't get the help he may need it won't be given to him if he doesn't get assessed and diagnosed.

You could ask the primary school he goes (or will get into when he's old enough) to keep an eye on him as that's where he'll be spending most of his time and that might open your wife's eyes more as it's not coming from you and coming from professionals in child care so to speak.

Rather than just telling her that YOU think he might be autistic maybe you could encourage her to look into it her self and do her own research that again will open her eyes more than anyone forcing their own opinion upon her if you know what I mean.

Hope that helps,

O.

Edit: Those traits you described are early signs.