jQuery moving car!

HTML

<script src="http://jqueryrotate.googlecode.com/files/jQueryRotate.2.2.js"></script>
<!DOCTYPE html>
<html>

<body>
<H1>Hey Reddit, Check out what I made today : Use the arrow keys :)</H1>
    <br />
    <p> Updates:</p>  
    <ul>
        <li>"Turn only when moving"</li>
        <li>fixed reverse key directions</li>
<li>reversing added</li>
<li>multiple keys now supported</li>
<li>smoother(than before) motion - stil not smooth enough</li>        </ul>

        <div id="container">
<!--<img id="carImg"  src="http://thumbs.dreamstime.com/thumblarge_459/126034361367I321.jpg" alt="Smiley face" width="80" height="80" />-->
             <div id="container">
<img id="carImg"  src="http://solidworksaudir8.com/assets/images/landingpage1/solidworks_car_top.jpg" alt="Smiley face" width="115" height="60" />
            
        </div>

        <div id="output"></div>

</body>
</html>

CSS

#carImg
{
    position:absolute;
}

li
{
 border:1px solid lightblue; 
margin-bottom:2px;
 margin-left:20px;   
    padding:5px;
}

*
{
    font-family:arial;
 padding:5px;   
}

h1
{
 font-size:2em; 
background-color:lightblue;    
}

JavaScript

var offset = -180;
var rot_step_val = 5;
var dist_step_val = 10;
var angle = offset;
var u = false;
var d = false;
var l = false;
var r = false;
var revConst = 2;

$(document).ready(function() {

    function handleKeys(e) {

        trace(e.which);

        if (e.which == 37) {
            e.preventDefault();
            l = true;
        }
        else if (e.which == 39) {
            e.preventDefault();
            r = true;
        }
        else if (e.which == 38) {
            e.preventDefault();
            u = true;
        }
        else if (e.which == 40) {
            e.preventDefault();
            d = true;
        }
    }

    function handleKeyUp(e) {
        trace(e.which);

        if (e.which == 37) {
            e.preventDefault();
            l = false;
        }
        else if (e.which == 39) {
            e.preventDefault();
            r = false;

        }
        else if (e.which == 38) {
            e.preventDefault();
            u = false;

        }
        else if (e.which == 40) {
            e.preventDefault();
            d = false;
        }

    }

    function fastLoop() {
        if (u === true) {
            revConst = 1;
            moveForward();
        }
        if (l === true) {
            rotateLeft();
        }
        if (r === true) {
            rotateRight();
        }
        if (d === true) {
            revConst = -1;
            moveBackwards();
        }
    }

    var key = setInterval(fastLoop, 25);




    $(document).keydown(

    function(e) {
        handleKeys(e);

    });

    function rotateToAngle() {
        $("#carImg").rotate(angle + offset);
    }


    $(document).keyup(

    function(e) {
        handleKeyUp(e);
    });


    function rotateLeft() {
        if (u === true || d === true) {
            angle = angle - revConst * rot_step_val;
            rotateToAngle();
        }
    }

    function rotateRight() {
        if (u === true || d === true) {
            angle = angle + revConst *...