Starting Stumper

1998 Dodge Grand Caravan, 120,000 miles. I love my van when it runs. About a year and a half ago, we started having problems with starting the van. I'd be driving around, go into a store, school, whatever, come out & the van wouldn't start. 2 things would get it to start: 1-leave it for about 18-24 hours & it would start as if nothing ever happened; 2-my husband could "rock" the van from side to side, get in & it would start right up. Took it to Dodge shop, they replaced the ignition switch, didn't help. Started happening more often, towed it to the shop 5 times (now my insurance dropped my towing coverage off), by the time it got to the shop, they were able to start it right up. Finally the service manager came out to our house the next time it wouldn't start, put it on his computer, decided the BCM was bad. He left & my husband went out 10 minutes later, "rocked" the van & it started right up. $350 later, BCM replaced, still having problems. Shop figures it's something either electrical (they'd have to go through & test all wiring to see where problem is- apparently nobody's too keen on that option), or something to do with the security system- which they apparently can't disable because of the way the factory installed it& its interconnectivity with other stuff). Skip to New Year's Eve. Van died in WalMart Parking lot, the next day it started, for the next 5 days, it died 3 more times. "Rocking" the van no longer is effective. Dodge shop has no tech bulletins on it, no clue what the problem is. Chrysler tells them to start throwing parts at it until something fixes it. My shop won't pull that kind of B.S, but we're still dead in the water. Called Dodge customer service, they said they had no fixes, but I could lodge a complaint. If they get enough complaints, they may work on getting a tech bulletin together for it. Fine, but I need my van now. Any input would be greatly appreciated.