wider spacers means longer bolts(i hope it is the right word ) and longer bolts are more stressed bolts
so you need better materials or bigger bolts,
of course mr. lambo knows a lot more than me about cars tecnical and it is not a problem for mr. lambo( or i should say mr. sauber ...) finding right bolts or parts for his lambo,
i only want to say to less experienced people be carefull with big spacers or you could have some troubles