.vehicleCats{ list-style:none; margin:0; padding:0; }
.vehicleCats li{ float:left; margin: 0 15px 30px 15px; box-shadow: 0 0 5px #888; width: calc(25% - 30px); height: 210px; }
.vehicleCats li h2{ font-size: 1.4em; line-height: 30px; padding: 0 10px; text-align:center;}

@media only screen and (min-width: 601px) and (max-width: 1100px){
   .vehicleCats li{width: calc(50% - 30px); height:auto;}
   .vehicleCats li p{text-align:center;}
}

@media only screen and (min-width: 0) and (max-width: 600px){
   .vehicleCats li{width: calc(100% - 30px);height:auto;}
   .vehicleCats li p{text-align:center;}
}