You keep saying we but really this is his space let him do it. 18 yrs old he can do it all I really dislike kids rooms done to my taste not theirs and at 18 he I am sure has opinions Love that desk BTW but does he need a desk? Is he still in school? We need to see the whole space in pics posted here in comments DO NOT start another post . My advice get your son's input and his work into this space . He is not a child and has his style already I bet

I like the sculpture a great jumping off point. Maybe a leather or wood headboard and some bedding he likes.

The car looks like it is for ages 8-12.

The metal sculpture looks like a dust catcher.
He is an adult.
Unless there are extenuating circumstances,he should be capable of choosing his own decor and furnishings.

Is the car the only art? If so, I'd put together ideas for his bedding, which is going to be a main color element in the room. You can get vintage car posters on Etsy, if you want some other options.

My son, now in his 20s, likes to display things like Lego creations, models, etc. He graduated with honors from a top tech school and Lego is the way he relaxes. I'd have assumed he'd have grown out of it a decade ago, but he didn't. So, make sure you have display space if that's something your son wants.

The desk you have there looks elegant, but there's no place for supplies or files and the chair looks uncomfortable for sitting for hours, which he might end up doing if he has a lot of work/class on Zoom.

Thank you for the range of thoughts. For those who thought this was a solo effort, it is not and it won't be. I/we have plenty of time until our new home is ready. He may find some other artwork that is to his taste (modern car).

Yeah, I get annoyed when people think I should stay out of my son's interior decoration. He appreciates the help. Besides, do any of these people know how hard it is to get an 18-20 year old guy to put up with styles he doesn't like?

Design a neutral guest room. At 18 he'll be gone soon and his specific interests really will be so short lived..he can accessorize and take it with him. This really needs to be an adult space to make it worth the time let alone the effort. At 18 my son was prepping for a dorm room and he looked to my husband to help him build a desk/loft combo. As a man he moved on from my input. The T-shirt quilt made from all his activities is still here. The guitar poster he purchased, I framed is still here.... His wife has spent more than a few discussions finding just the right place for the art he created/collected between then and now!!! hahahahah

The car art is too juvenile. i would skip that.

Until your new home is ready? What home is the bedroom to be decorated in? new or current?

I would pass on the car or any kind of theme for a 18 year old.

My o h likes cars and he's an adult and he will have a car model in his office on his side and some times he likes some NASCAR stuff he has a NASCAR mug that he has there

Honestly how long will he be in this room? Treat it like a dorm room. Provide lighting, desk, nightstand, dressers and a bed. Let him provide bedding and art to personalize it.

I would look to use real art prints of sports cars to do a couple above the bed and keep it simple. There are some nice options he can choose from on the Great Big Canvas website in black and white or neutral shades.

www.greatbigcanvas.com/category/transportation/car/sports-cars/

I do not know why Mom's want to decorate an adults bedroom at all. He can choose everything and do the work then the space is his . When he moves out you can do wahtever with the space . We have had international students for the last 15 yrs the bedrooms are done each time ith a paint if needed new bedding if needed both neutral then we add what the kids need. Over that time some kids love a desk some not so much we have always had boys and honestly they are pretty easy to please as long as the bed is comfy , they have good internet and a TV We give them a chair that is comfy to sit in and some use it some not ASK him what he wants and if he does not care then leave it be .

I wonder about waiting on the artwork until the room is finished - do you have the furniture picked out yet? a nice chair with an ottoman can be a comfy addition, space permitting. I agree with @Sigrid to think about storage for the desk -

FWIW I think it’s nice you’re creating a room that you son will like (my 23 old son is moving to NYC next year and wants me to help him with his apartment and I’m chuffed)

Of course you and your son are doing this together..thats wonderful..Both my adult children are married and they still want my help and advice on decorating..have fun!

thank you for the advice, have also found modern car prints on etsy.

I like that you and your son are designing this room together, especially since you seem to have very good taste according to the inspiration pic you posted. Since you are moving in the future, this is a good time to experiment with interior design. I don't have any ideas to contribute for now, but will check back.