Daniel,
Be cautious when comparing your website stats to any other dealer's stats. It will lead you draw conclusions that can ruin your business. If you'd like to know why, it's all in here. forum.DealerRefresh is full of examples where we talk about this.
Your best stats are your historical stats. Look back and track your progress (or lack of progress 
It's the cleanest data you'll have.
Some notes:
Time On Site is highly dependent on the dealer's profile. Uncle Joe Rule #121: "car dealers are like snowflakes, no two are alike"
Conversion Rate is a sloppy number. You want to focus on which forms are being submitted. Focus on the forms with the highest closing rate. Try to ignore the others that waste everyone's time.
Speaking of conversion rates, if you improve your site, EXPECT your crappy leads to convert at a lower rate.
Bounce rate is YOUR problem. What I mean is looking to other dealers wont help here. Next, a service customer coming to your website for a phone number is a bounce. Next, look for bounce rates on PAID ADs. Squash any paid ads that have a bounce rate that is > 2x your avg bounce rate. After this, you can pretty much reduce the importance of bounce rate.
HTH
Joe
