Here are a few tips. If a two level carrier try to get the top most forward space. This will assist in preventing these two problems.
1. I once received a pristine 968 Cab shipped across country with oil on the gray top, windhield and hood from the severely leaking car above it. the problem is only somewhat less if you get one drop of oil. How many cars don't drop one drip on a 2500 mile 6 or 7 day trip?2. Ever seen a truck driver put a Porsche on a ramp? Bye Bye clutch. In the front position. He puts it on once and takes it off once. Otherwise it can be on and off 3 or more times which also means re tie down three times which means more opportunity for straps, chains and other restraints to bang your paint your wheels and your pocketbook.
Here are some other tips. Arrange your insurance including comprehensive and collision before the trip not on delivery. Buy $100 deductibles until car arrives and inspection complete then increase them to $500 or even $1000 after the major risk is over. Call your broker and make him at least verbally tell you that the coverage applies during the haul then he can't deny coverage if something goes wrong. Don't even bother to have the hauler specifically insure your vehicle but DO make sure he is insured by requiring a certificate in advance. His insurance on your rig is useless and costs you, not him, money.
Hire a big guy like Interstate or someone who advertises in Panorama or other car publications. If they are offering horrible prices then at least make sure you hire someone who is actually doing the haul, owns the business and is maybe even driving the rig. Do not farm out to a broker because when the damage comes you won't even have anybody to talk to. Get reference from forum readers or other Porsche or car people before signing a contract. Side benefit. If you are dealing with the owner he may allow you or the seller to drive the car up the ramp.
As to sending the money before delivery ask the seller to trade places with you and deliver prepayment. When he tells you how crazy you are gently point out that you are actually crazier to trust a stranger and ask how he would remedy the situation or what he would do if situation were reversed. I once concluded one of these by meeting halfway (Amarillo) and eliminating the hauler. Another was resolved by sending half the money. Most of mine had resolution because they had known refernces in PCA or the Forum or elsewhere. Discussing the subject with seller can usually solve it because he doesn't want to lose the deal either. Sometimes you have to wing it and that can be ugly for a few days.