Car loan solutions, no credit or W2?

I figured I would send a Hail Mary question to this group to see if I am overlooking anything. My son is trying to buy a truck. I’m open to helping in some way.

I am debt free except my home. I contribute the max to my 401k and HSA and put some money (10-20k per year) into a brokerage account while also paying $1k extra each month on my mortgage. My own car is a 2023 so no replacement needed soon. My credit score is 850 and my w2 income is over $200k/yr.

My son (21) does not have his own credit or any debt. He also doesn’t have a W2 job or verified income because he has worked as a contractor and just finished school last in December. He is not getting a W2 job but will be doing quarterly taxes this year to make his 1099 and other self employment income legit. He is still living at home, so DTI is no problem, just not having 2 years of income or his own credit score. He didn’t apply for a loan. He typically makes $4-8k per month pretax, so a $500/mo car payment would not be an issue for him.

I thought I could probably just co-sign since he didn’t, you know, have a job or his is own credit, but the loan officer didn’t seem to think that would work to get him approved.

I could just take out a loan, but I don’t really want to. I could buy a vehicle cash and make a formal loan to him. He is open to waiting, or maybe getting a w2 job short term to qualify. (This is probably the right answer). He has a small truck but a full size /HD truck is needed for his business to tow trailers 1+ times a month. He borrows from his boss or his dad now, but obviously it’s not ideal. His truck is worth under $5k and he’s looking at a $20k option, which still doesn’t give you a very new or low mile truck that are easier to get loans for.

Any other loan options for him that I haven’t thought of? He also has a new LLC but with a new biz and no personal credit, I wouldn’t expect him to get a business loan, either.