I have no idea why but it seems to work with the code from here (little modified) adding in the plugin file after:
var autocomplete = new google.maps.places.Autocomplete($el,{'.$opts.'});
var pac_input = document.getElementById("geo_search");
(function pacSelectFirst(input){
var _addEventListener = (input.addEventListener) ? input.addEventListener : input.attachEvent;
function addEventListenerWrapper(type, listener) {
if (type == "keydown") {
var orig_listener = listener;
listener = function (event) {
var suggestion_selected = $(".pac-item-selected").length > 0;
if (event.which == 13 && !suggestion_selected) {
var simulated_downarrow = $.Event("keydown", {keyCode:40, which:40})
orig_listener.apply(input, [simulated_downarrow]);
}
orig_listener.apply(input, [event]);
};
}
_addEventListener.apply(input, [type, listener]);
}
if (input.addEventListener)
input.addEventListener = addEventListenerWrapper;
else if (input.attachEvent)
input.attachEvent = addEventListenerWrapper;
})(pac_input);
$(function(){
var autocomplete = new google.maps.places.Autocomplete($el,{'.$opts.'});
});