cj2112

First let me say that child support is to support the child, not to pay for the car that got repo'd.

Having said that, if he has the child half of the time, then he is providing for the child half of the time. What makes you think you're entitled to the full amount of support, when you're only providing for the child half of the time?

I would expect that the ex is probably going to, at the very least, file for a support reduction (which he is entitled to) and possibly for full custody.

You must look past your personal differences with your ex and decide if he is better equipped at this point in your lives to be the custodial parent, or if you are. This doesn't just mean financially (although that should certainly play into it) but socially (for the child) and emotionally. If the answer is yes (and I view claiming not to know as a cop out) then you know what you need to do.

Just to address a couple things that Demeter said....
he doesn't have to prove you unfit in order to win custody, just that he is the better placement option. Also your son is 6, unless your son accuses his father of abuse, what he wants will hold little if any weight as to the judges custody decision . The kid isn't old enough to make decision about what he wants.

I've been there, I'm raising my two kids on my own (now 10 and 12) and have had custody of them since they were 21 months and 4 y.o.