The top is also adjustable for height
THe rear lock down bayonettes are adjustable. There is a threaded part to the spear end and it can be raised or lowered (when off the vehicle) by turning them.
Hope this helps...
1985 Mercedes 500SL Euro (Gray market)
1995 BMW 520i Euro (Gray market)
1992 BMW 525it Wagon
1994 Honda Del Sol Si