I can only chime in on what would be on my list
1: centa drive upgrade.... ON MY LIST for next year. I already have over 10,000 miles
2: I have already lost way too much hearing.... no change
3: olhins... a lot of $$, but maybe I just am unaware of how much better he handling could be.... but if you view my you-tube it took the dragon well
4: upgraded cams.... from what I can see they just help with the start up by lowering the compression
5: steering... Once again doubt as I think it helped the early cars with the bump steer issues
6: bevel box... I have only heard the clunk a couple of times...
7: fur lined flight jacket.... got that for Christmas