Are they paying for a rental in the interim? What about storage?
In most states, they *should* be covering both of the above (the former being a loss-of-use claim). They will presumably try to get it out of storage and off to auction ASAP, even before settling with you; IMO, you should be careful to avoid that possibility (among other things, don't sign the title over until you reach a settlement). The fact that their cost increases as the clock ticks should help encourage them to reach a reasonable settlement.
In some places, you may also be entitled to payment for the cost of registering the replacement vehicle, documentation fees associated with a dealer sale, etc; it may be worth your time to see if you can get an initial consult with a local attorney to understand what you should be asking for in your jurisdiction.
If you want to avoid the additional cost of selling and replacing parts and accessories not installed at the time of impact, your best bet is to replace the vehicle with a like vehicle, IMO. I realize that may be easier said than done, particularly in the current marketplace.