[Baker]

Look it over top and down and:

1. Check the trunk underneath the carpet by the spare for rust / water damage.
2. Look very closely at both rear quarters, rust hides under the bumper before it creeps out frequently.
3. Shocks and springs - if there are aftermarket springs but original shocks guess what might be blown?
4. Wiring - is it hacked to [crud]? Does it look professional?
5. How does the swap run? Does it shake the whole car constantly?
6. If it has a sunroof (I don't remember sorry) make sure that works properly and looks good.
7. Check for bondo using the magnet trick.

Excellent checklist!
That should be a sticky for buying a Crx, or ANY Honda for that matter!

Just a note that, If it is a REAL SI, it will have a non-glass, factory power sunroof. Check that for rust on the panel and be sure it shuts properly.