Anything especially auto work is negotiable, how successful you are with it will depend on your negotiation skills and their openness to it. They can take less margin on product and labor is where they can really save you money. I was able to talk down a well known local installer by offering to pay cash and for doing everything at once. Also helps to build up rapport with installers as you shop around.
The way I see it, I didnt like any of the colors offered for the M3P, black was the only one tolerable but I would have wrapped it to protect the shiny black paint which would cost extra $$$ plus I would have to lose the $1000 upgrade fee and the $7500 tax credit which equals $8500. So I figured get the SG and you'll have saved $8500 for your wrap/tint/ceramic. I got a guy down to 4-5k for everything which will save me $3500-4500 of that $8500. That figure can change once I get him my vehicle but at least I have the table set for when I pickup my car. These guys all look at eachothers pricing, Tesla's wrap pricing and know how popular it is with Tesla owners plus the perception we all have tons of money does not always make it easy to get a good deal. I had lesser known installers try to charge me 8k to 10k for the exact same service, just make sure to shop around ALOT.