You should have received a copy of the current bylaws with your property purchase documentation, which will show if he has permission to park and to erect a sunshade.
If nothing shows he has permission for neither (unless granted under a normal motion at EC or AGM and if so it can be revoked with another motion removing that permission).
Suggest a compromise let him keep the sunshade but stop parking his car their. His being their 10 years is meaningless except that he ought to know better (having 10 years strata experience).