Just a bit on diminished value claims. I'm currently pursing one in California. If you are at fault, then you have no claim because 99.9% of insurance policies specifically exclude diminished value claims. Your insurance company is only required to repair the car (or total it). However, if you are not at fault (i.e. someone runs into you), then you can file a claim directly with the at fault driver's insurance company. Your own will not help you, because your policy excludes it. The reason you can seek it with the at fault driver's insurance company is because you do not have a contractual agreement with them excluding those claims.
Rental car reimbursement is similar. Your policy probably limits you to $50/day for 30 days or so. If you go directly to the at fault driver's insurance company, you do not have a contractual limit. The downside to this is insurance companies are bastards, and they will lie to you and say diminished value claims are illegal, rental car limits are set by law, etc. Don't believe them. There are no limits written in the law, just in your policy.