Do your roof rack cross bars clamp on to the existing luggage rack bars on the roof or to the gutter? I've got cross bars that clamp on to the roof bars but all I've put up there are some skis and snowboards, I'm a little leary of putting a canoe on there, I wasn't sure how string the factory roof bars were.

__________________
1985 300TD-euro 352,000 mi
1974 240D (1?)52,000 mi - has a new home now