RewriteRule ^brands$ brands/ [R=301,L]
RewriteRule ^brands/$ /brands.php
RewriteRule ^brands/([A-ZÆØÅæøåa-z0-9-]+)-([0-9]+)/$ index.php?manufacturers_name=$1&manufacturers_id=$2 [L,QSA]
RewriteRule ^brands/([0-9]+)$ index.php?manufacturers_id=$1 [L]

xxx.com/brands/brand-id