What is a good and recommended way to dynamically build a query inside
stored procedure?

For example a typical web portal search engine. user can select one or
many input parameters for a search.
For example car_model, fuel_type, color, gearbox_type etc. then into
select statement where part should be put only those what have value.

I started to look at first at "EXECUTE STATEMENT". but then in
documentation found sentence "Operations will be slow because the
embedded statement has to be prepared every time it is executed.".

then thought probably there is a better way? how to do it?