<table width="397" border="1" id="dbAuto">
<tr>
<td width="159" id="nazva">Марка</td>
<td width="222">0</td>
</tr>
<tr id="pop">
<td>Jasmin</td>
<td>1</td>
</tr>
<tr class="del">
<td>AZA</td>
<td>2</td>
</tr>
<tr class="del">
<td >VOVA</td>
<td>2</td>
</tr>
</table>

v
ar parentElem = document.getElementById("dbAuto");
var beforeElem = document.getElementById("pop");

var tr = document.createElement('tr');
var td1 = document.createElement('td');
var td2 = document.createElement('td');

var text1 = document.createTextNode('Модель');
var text2 = document.createTextNode('Модель-1');

td1.appendChild(text1);
td2.appendChild(text2);
tr.appendChild(td1);
tr.appendChild(td2);

parentElem.insertBefore(tr, beforeElem);