$530 for roof rack and bike attatchment seems to me like alot of $$$.
Personally, I just would fold the back seats down, take the front wheel off your bike (assuming its got at least quick release) and that way you save $$$.
A few weeks back, I can fit two mountain bikes into my Jazz with seats folded down and front wheels off - although Honda claims you can fit 4 x standard bikes in the Jazz.
If you buy the roof rack, buy yourself a nice set of high beam lights (which can beam up to 600metres) and place it on your roof rack - your car would light up the national park if you cruise through there!
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