I, and most of the attendees at the European Events regularly drive over 2000kms in a week for our events. I do classic car rallies in my Pagoda as well. One day rallies typically require 350-400km's, and I'm doing a rally in August which will cover >2000km's in 5 days. Before I start I have the car serviced, brake fluid replaced, new oil, suspension checked.
Then in September we'll have the European event, another 2500 km's to the South of France, albeit at a more leisurely pace. If the car survived the rally ok, I probably will not even service the car for that, other than checking oil, ATF, coolant and tire-pressure.
I carry sparkplugs, a fanbelt, and a fuel hose (from tank to pump) as spare. The latter because there was a bad batch produced. I run a 123 ignition which has not failed me in over 20.000 kms of travel. I have the original distributor/points/etc but did not bother carrying it as a backup. I have no spare fuel pump.
I carry duct tape, tie-wraps (can replace gear leaver bushings in a pinch) and a basic tool kit, including stuff to fix the odd electrical wire or connection.
The best advice is: drive long distances before taking part. If the destination is mountainous, include mountains. If it is wet, drive it through the rain. If you're confident about your car, that's the best.
Oh, and by the way: the Pagoda is an excellent travelling companion. You can get out after 500 km's relatively relaxed. It is fast enough, yet comfortably roomy. Just a little bit of noise. If the rally takes place when top-down driving is unlikely, consider driving with the hard top on. It gives much better visibility (ideal for the navigator) than with the soft-top. It's not as agile as a 911 or most Alfa Romeo's but you have plenty of acceleration power if you dare to put your foot down. I enjoy it tremendously during rallies. It is a bit thirsty gas-wise, so if gas stations are not plentiful, it may be a good idea to put a spare 10-litre jerrycan in the back.
Peter