Ive got to totally agree with BKL! Anytime the cost of the repair is as high as it is going to be on yours, they usually always total the vehicle. Attorney or not, I'd make sure they "total" the vehicle and cut you a check, PERIOD.
Unless you have injury from the accident id totally stand clear of an attorney, their service isn't needed at all! You'll also find by using an attorney, especially without any injury you'll end up spending money for his/her services that you wont be able to recover from the other party involved. I did see where you stated you did suffer some injuries or that you did suffer some pain. Did you go directly to the hospital via ambulance at the scene? If not, then I'd really stand clear of the attorney. You'll also find that many good attorneys wont want to take your case on unless you do have verifiable injuries that are supported by a doctor.
These are only based on my personal experiences in similar situations. But one thing for sure that I would make certain of, is getting the SS closed out as a "total" loss. Also you asked about getting diminished value of the SS. Here's how that works. If your SS is brand new which of course it was or even if you had it for a longer period of time. Your chances of receiving damages by way of diminished value is pretty slim to none, here's why. If your vehicle is repaired with mostly factory parts and named brand parts such as SS branded parts there is NO diminished value extended.
And here's something to think about. Would it be worth it to receive diminished value by allowing a body shop to use parts that aren't SS branded? I would think it wouldn't be worth it at all to go that route especially if you think you'll be selling it down the road. Most people will want all original branded factory parts. Also loss of use would be considered if it was your only form of transportation and that of course would have to be proven by yourself to even be considered for that coverage. Its even hard to get loss of use when you're driving a automobile, not to mention the SS isn't considered to be an automobile. Some people also get confused when it comes to receiving a loaner vehicle as well. Most insurance companies will "try" to put you in a similar type loaner vehicle as to the one you were driving. However the industry standard now is to allow for a loaner vehicle priced from $30 to a max of $40 bucks daily.
Pretty much all the info I've provided for you here is exactly what hiring an attorney will do for you. Im in NO WAY representing myself as an attorney in this communication either. I'm only posting facts based on my personal experiences in life that I've gone through myself. The last time having gone through this being approx 2 years ago. I'm sorry if what I've explained to you is hard for you to believe or accept or if it makes you angry. I'm only trying to pass pertinent information on to you based on my own experiences as stated. If you would like more information or help from me, please pm me and I'll be more than happy to help you out. I'm truly sorry for what happened to you and well as your SS. I know it totally blows beyond all to have something like this happen to you! Take care and please feel free to pm me for any additional information, take care!