How to remove the widget title and list style from ad-engine

you can add some styles like these at the end of style.css of your theme:

#ad_engine-3 .widgettitle { display: none; }
#ad_engine-3 ul { list-style-type: none; }
#ad_engine-3 .ad_caption { display: none; }

That gets me closer but now it’s doing some odd positioning of the ad – take a look: https://www.largecarmag.com/wordpress/

you can influence the position by adding margins to the style;
example:

#ad_engine-3 { margin-top:5px; margin-right: 5px; }