<VV> Why "crossed" lap belts?

[Wrsssatty at aol.com]

Interesting thread regarding GM's recommendation that the inboard, female  
(buckle as opposed to tongue) portion of the lap belts be "crossed over" 
(i.e.  driver to use the one bolted behind the passenger and vice versa).  I've 
 always wondered about that.  The only possible explanation I could come up 
 with is that maybe it was intended to minimize the likelihood that 
occupants  would slide out laterally in the likely event that the door would pop 
open  in a crash in the days before Chevy put safety door latches on their 
cars  (1st done in model year '63).  Does anyone have access to official 
Chevy/GM  seat belt instructions for model years '64 and/or '65?  I know that for 
my  '63s such info is not contained in the Owner's Guide but on a separate 
card that  was to be inserted in the glove box should the optional, 
dealer-installed  "Custom Feature Accessory" seat belts be purchased.  I think a card 
was  likewise used for model year '64 and it might even have been a carry 
over from  previous years.  Who can tell us about '65?  Was seat belt usage  
discussed in the Owner's Guide for '65 or was it still on a separate insert  
card?  And what instruction was given in regard to whether the belts were  
to be crossed?  
 
~Bill Stanley