I knew this would happen..

[wolf_Q]

Wow Isabel, I'm so sorry they are treating you this way. You've dealt with enough. He's YOUR child, of course you want him to live with you, you're his mom. I hope they come to understand this, sorry that you have to go through all this. {{HUGS}}

[cyber-sibes]

Oh Isabel, having dealt with wacky in-laws thru a divorce, I can relate to how crazy-making this can be. Bottom line; You may need to be blunt and remind your MIL over and over that as his Mother YOU decide where and when he goes somewhere. "Weekends or nothing" option sounds fair enough, as long as they play by YOUR rules, not the other way around.
I wouldn't even give the car thing a second thought - its your car to do with as you see fit, certainly not something you need to be stressing out over right now. Sending you good thoughts-

[kitten645]

Isabel, I can't imagine your pain or your sons. But as you've said before you are gaining your strength for him. Be strong and don't let others manipulate your life despite what they believe to be best intentions. You know what's right for you and your children. Karen said it best. Know that we are all behind you. You deserve all the best.
Claudia

[Daisy and Delilah]

{{{{{ISABEL}}}}}

I wish you all the best. You have been through enough already. Your MIL needs to have some respect for you and let up on soothing her feelings. Stand your ground!!