AdrianStewart- You *can* spot polish, remove isolated scratches, etc. It's basically all I do on our vehicles 99% of the time.
You just rub the marred area with an abrasive polish until you've leveled the paint, like sanding a scratch out of a piece of wood using sandpaper.
Deep Crystal Step #2 won't do it, it's nonabrasive.
Scratch-X is the standard OTC answer for this and oughta work if you put the time and effort into it. I prefer products from 1Z and/or 3M but that's just personal preference. You use the abrasive product of your choice until the scratch is something you can live with. I generally use a MF for this, but others prefer foam, or even terry as it provides more cut. Then wax the area, going a ways beyond the part you polished so the new wax blends into what's already there.
No need for a high-speed buffer in most cases (I remove fingernail scratches from behind doorhandles by hand on hard Audi clear). No need for heat (I never work in the sun, only in a climate controlled shop) unless you're using a rotary-only product that *requires* heat to break down, so just use something that doesn't need that. All it takes is a lot of time and determination and a little common sense.
Gotta differentiate between Meguiar's Deep Crystal Line and their professional line. VERY different things...two products that were mentioned are the PRO line #2 and #3, which I'm familiar with:
Note Meguiar's #2 Fine Cut Cleaner has recently been reformulated to work by hand/PC as well as by rotary. Make sure you get the *NEW* version if you're working by hand. It might be good for this job. #3 Machine Glaze is a nonabrasive "pure polish" (similar to #7/Deep Crystal #2) that's formulated so it won't dry out too fast when used by machine (works fine by hand too). Being nonabrasive it's not the product for this job IMO. For more info on Meguiar's products you might to to
Meguiar's Online . It's easy to get mixed up with some of their professional products. If you don't know which Meg's product to use, maybe you oughta get your advice straight from them.