LOOK OUT, THIS IS A TUTORIAL ON REQUEST.
IT IS NOT TESTED ON VERSION 2+

Not everybody wants more than 12 pictures, some do...
Here is a small tutorial to learn how... Let's do it below:

Open up your PHP MyAdmin, and go to the table #__rduatos_information. (#__ is your prefix)
-Add some entries first (imag13, image14, image15, image16 and so on) Make them a VARCHAR 40.




Lets open up the next file to upload them correctly "/administrator/components/com_rdautos/models/application.php"
Go to the next line (233) in your file: 
$file12     = JRequest::getVar( 'pica12', '', 'files', 'array' );
Add more of these lines in the next order: file13 must be:
$file13     = JRequest::getVar( 'pica13', '', 'files', 'array' );
And so o, depends on the count of images.

Done? Scroll down, you will something like this:

if (isset( $_FILES['pica12']) and !$_FILES['pica12']['error'] ) {
    UPLOAD_autos::uploadhandler($id, $file12, $row->image12, '12');
}   

Add more of these replace the numbers by the number of your picca, let's say number 13 must be like this:

if (isset( $_FILES['pica13']) and !$_FILES['pica13']['error'] ) {
    UPLOAD_autos::uploadhandler($id, $file13, $row->image13, '13');
}   

So the uploader knows what to do now...
Close application.php now, we're done here.

Open up the next file: "/administrator/components/com_rdautos/views/application/tmpl/form.php

Add some boxes here, some upload fields like this: <input type="file" name="pica11" id="pica11" />
I guess you know where to put these boxes, if you have designer-view you can put them below the existing fields.
Off course you need to replace the numbers again, 13, 14 and 15 depends on how many uploaders you want.
Example of picca 13: <input type="file" name="pica13" id="pica13" />

Administrator files are done allready, this was so easy to do, just try them now :-)

Front end files to edit:
Open the next file: components/com_rdautos/views/application/tmpl/default.php

Add some boxes here again, like this: <input type="file" name="ad_picture12" id="ad_picture12" />
replace the numbers with the corresponding numbers again. (Like before, don't rename the fields!!)

Save and close the file and go to: components/com_rdautos/models/application.php
Look for the next line again, and add some lines again, example is below (image 13)
$file13     = JRequest::getVar( 'ad_picture13', '', 'files', 'array' );

Look for the next lines again, and add some of these line also, don't forget to replace the numbers again...
if (isset( $_FILES['ad_picture12']) and !$_FILES['ad_picture12']['error'] ) {
    UPLOAD_autos::uploadhandler($id, $file12, $row->image12, '12');
 }

This should do the trick :-)
Good luck!