J.G.
I attatchment parent, too. It can be very difficult when they are that close. To me it sounds like your oldest is in need of some one on one time and has found a way to get it. Make sure you spend some time with just him (when you youngest is down for a nap?) and you may need to find a way to move him into a different room at night. Even if it is a playpen in the living room.
I caution you: Don't get into the car ride habit. My two year old got trained to nap in the car (I deliver flowers and she goes to work with me) and now she will not nap out of it. Try a swing instead, was the only thing that worked for a little girl I babysat.
Make sure that daddy is getting up with them his fair share of the time too- I understand he works, but so do you- 24hrs a day with no time off and no sick leave.