Keep requested/entered url with add_rewrite_rule

Okay I figured it out. Instead of using this rewrite rule:

add_rewrite_rule('^somepage/([^/]*)/([^/]*)/([^/]*)/?','index.php?p=27&target=$matches[1]&arrival=$matches[2]&departure=$matches[3]','top');

I now use this one:

add_rewrite_rule('^somepage/([^/]*)/([^/]*)/([^/]*)/?','index.php?pagename=somepage&target=$matches[1]&arrival=$matches[2]&departure=$matches[3]','top');

And now everything works like I wanted it to. Obviously using the page id instead of the page name was the problem.