"Bob" wrote in message
ups.com...
I just got a Sienna minivan and when I save up some money for gas

LOL....just finished shopping for minivans myself, and I know what you're
saying there! Everyone said the Sienna's are great, but we decided to go
with a Chevy Venture so that we could actually afford to go places after we
pay it off. :-)

I
hope to carry my Old Town Pack ( 12 foot - 33 Lb ) canoe to the lake.
I am looking for brackets that will mount on the rails to keep the
canoe from sliding side to side. The rail shape is NOT round or square,
it's () , turn 90 Deg. Toyota parts said that they don't have any
accessories for these rails.

There are several options. If your canoe's tied down properly, shouldn't
need anything to keep it from sliding side to side on your rack. That's the
cheapest option.

If that makes you nervous, the most expensive option is Yakima or Thule
gunwhale brackets--you'd need to check if any sort of adaptor would be
needed to mount them on your factory bars. A somewhat cheaper alternative is
the Riverside cartopper blocks--they make a set with a slot to accomodate
your standard elliptical factory rack bar.
http://www.rei.com/category/4501512.htm (if you've already got tiedown
straps you're happy with, you can get just the blocks). The cheaper-still
alternative would be to make something yourself similar to the Riverside
blocks out of closed cell foam.

Another problem is the front tie down! They don't have a bummper up
front. Only plastic parts, that would bend if I tried to wrap a rope
over them to get to the underside. So I plan on two wide side to side
straps around the middle of the canoe to the roof rack, two short
straps from the rear of the canoe to the roof rack, to keep it from
sliding back, and maybe a tie from the back to the tow bar reciver.

I highly recommend reading both "cartopping your canoe" and "more cartopping
tips" at http://www.paddling.net/guidelines/, and look at the various setups
for front and rear tiedowns. Remember that you have to worry not only about
keeping it from sliding back when you're moving forward, but from sliding
forward when you're braking.