Lil, you are giving him more than I could ever afford to give my kids for birthdays. I personally feel nobody should buy a car for a child. They learn good values if they save up for a beater and learn nothing except mom and dad will be a bank for them if a new car or other very expensive gifts are given. in my opinion it isnt even good to do this for a hard working adult child. Actually, often they will not work so hard if we hand them gifts. Entitlement creates many difficult kids.
You have spent more on this child, who still isnt trying very hard, than most parents ever do. You should not feel at all guilty. He should feel very grAteful to have you and for all you and jabby are able to and willing to do to save his buttocks from homelessness. 21 is only a milestone to me if you are moving on, say, from college to your adult life. 21 can mean adulthood or just be some number that allows our difficult kids to legally drink. Probably not such a terrific thing.
I feel our constant love for all of them, even during tough times is a big enough gift, and I know it is one they appreciate. And im sure your son appreciates your unrelenting love and kindness too.
The best things in life money cant buy. I am just one mom in a haystack, but I never did understand why some parents felt tne need to provide their teens even with items they dont need and wonder if it is good for them..or if somehow it makes US feel better.
Just my dumb thoughts, possibly worth nothing.
You have a nice birthday plan. As always JMO.