couple ?'s on my mums 2001 'burban
 

Ok, well recently my mothers suburban is applying anti-lock brakes randomly when I turn the wheel sharp like when you're pulling into a parking space. We've already had this issue fixed this past summer(forgot what exactly was replaced).

I'd like to replace the stock subwoofer in the trunk on the left side wall, is the specs of that speaker so I can get the same kind without braking anything.
And the passenger front door speaker is distorting the high end at lower levels, but at medium-high levels, it's ok. whats the deal?

And do these engines (5.3l Vortec V8) burn oil? It seems like this one does and my brother told me that most GM made engines burn oil for no reason...