You can always sue, the question is can you win. And if you lose will you owe them their legal fees which is likely since there was a contract involved which you should carefully read, including all that "fine print" on the back in gray ink that is barely legible. That said, if you noticed the car did not have enough ground clearance when you loaded it, you were probably under a duty to abandon the project right then and not risk further damage to your car. Even if you successfully sued them you may find that a Judge will attribute most of the damage done to you for towing the vehicle after realizing that it didn't have enough ground clearance at the start when you loaded it. You may want to check with your own insurance company and see if they cover any negligence on your part. That may be the best way to resolve this matter.
I would tend to agree with the previous answer, but would want additional details. Depending upon the amount of your damages it may be worth while to bring suit. The recovery in small claims court is capped at $6,000. I would recommend that you contact a Fort Wayne attorney for a free consultation. I think it would be prudent to read the agreement you had with U-Haul.