I hope your wife is OK and that you soon sort out your car troubles.
When the dust finally settles and you get back to thinking about kayaks and car racks, you should (as already suggested) consider getting a 'stacker' system, rather than bothering with J cradles. Your white water kayaks are perfectly suited for a stacker, which coincidently also happens to be cheapest option for transporting multiple kayaks. Stackers are available from Thule, Yakima and (ahem) Sportrack:
which often can be found on special at Canadian Tire.
The Kayak Wing
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