Just to be a wise guy & stir up a little controversy, If a driver pays attention & practices defensive driving,& defensive parking, & I mean DEFENSIVE, as well befits the driver of a small & very fragile & expensive to repair car - you will rarely need to use a horn. LBC's are much like motorcycles in this respect. Better to anticipate problems & avoid them than to use the horn when it is nearly too late.
On a more serious note; the above advice is good.
D