<select name="mark" class="jsSelect">
    <option>Марка 1</option>
     <option>Марка 2</option>
      <option>Марка 3</option>
</select>
<select name="model" class="jsSelect">
    <option>Модель 1</option>
     <option>Модель 2</option>
      <option>Модель 3</option>
</select>
<a href="{9 | url}" data-href="{9 | url}" class="jsLink">Подобрать</a>

<script>
    const selects = document.querySelectorAll('.jsSelect'),
               link = document.querySelector('.jsLink');
    selects.forEach(el => {
        el.addEventListener('change', () => {
            let values = [];
            selects.forEach(el => {
                values.push(el.value);
            });
            if(values.length){
                link.href = link.dataset.href + '?mark='+values[0]+'&model='+values[1];
            }
       });
});    
</script>

[[+image_absolute:phpthumbof=`w=350&h=195&zc=C&f=webp&q=10`]]

case 'OnHandleRequest':
       if ($modx->resource->cacheable == false) {
        $pdoTools = $modx->getService('pdoTools');
        $pdoTools->config['useFenomCache'] = null;
}

{set $getR = '!getRemains'|snippet:[
 'id' => $id, 
'option_size' => $value, 
'strong' => true
 ]}

{if $getR > 0}
1
{else}
0
{/if}

{'msOptions' | snippet: [
                'product' => $id,
                'options' => 'option_size',
                'tpl' => 'tpl-msOptions'
            ]}

{foreach $options as $name => $values}
    <div class="options-title"><b>{('ms2_product_' ~ $name) | lexicon}</b></div>
    {foreach $values as $value index=$index}
        <label class="options-label">
            <input type="radio" value="{$values[$index]}" name="options[{$name}]" {if $index == 0}checked="checked"{/if}/>
            <span>{$values[$index]}</span>
        </label>
    {/foreach}
{/foreach}