There's many ways to protect your paintwork and keep it in good condition, and each has it's own set of advantages and disadvantages.
Here's some of the more common approaches:
Paint protection film
The basic idea here is very simple - a layer of protective film is applied to the outside of the paintwork, acting as an extra layer of protection between your paintwork and the elements. Just like the screen protector on your shiny new smartphone basically. You can even get it in different colors if you want to change the overall look of your car without paying for a full respray!
Advantages
- It's cheaper than a full re-spray, so if it gets damaged over time you can just have it removed and re-apply a fresh layer
- Protects against all but the heaviest of stone chips and light paintwork scratches
- You can apply it to only the most vulnerable areas of the car (such as the front bonnet/bumper) if cost is an issue.
Disadvantages
- It's not cheap, and unless you want your car to look..well, terrible you'll want to avoid anywhere offering suspiciously cheap services as badly applied film not only looks bad but can result in actually doing worse damage to the paintwork than anything you're trying to protect from. (Tales of poor quality fitters leaving behind knife marks in the paint from where they have been trimming the film are all too common! As are bubbles, frayed edges, and if it's not applied properly water can get behind the film and get trapped). This is definitely not one for amateurs to try at home!
- The film can't be repaired - if it gets damaged (say from a nasty stone chip or bird droppings) at a minimum you're going to have to get the full panel's worth replaced.
- Bird droppings become even more of an issue, while the paintwork is protected they corrode the soft plastic more easily than the paint underneath so if you don't get it off quickly you'll have to get that panel re-wrapped.
- Many of the things that cause swirl marks - in particular mechanical car washes create a spider-web of fine marks on the film. Yes your paint is still fine but it will look terrible unless (you guessed it) you have it re-wrapped.
- Partial applications will always stand out from the rest of the paintwork - the layering of an additional, different, material on top of the paintwork's clearcoat will change the refractive index ever so slightly, making it a slightly different shade and once you've seen it it's really hard to un-see!
- Any damage that actually damages the panel underneath (such as accident damage) will be more expensive to repair since you'll need to get that panel re-wrapped after repairs.
- Any damage that's on the paintwork already (scratches, swirl marks, etc) gets trapped under the film and if you decide you want to get rid of it in the future.. (don't make me say it again)
Wax and similar sealants
Like film the basic principle of waxing a car is that you're adding a layer of additional protection on top of the existing paintwork. Only this time it's a chemical rather than a film.
Advantages
- Cheap! Even getting a professional to do it for you is only going to cost you a few hundred rather than thousands.
- You can try this at home! If you are prepared to put the time and elbow grease in you can do this yourself, sites like Detailing World will provide you with more information then you ever wanted to know about different products, and ways of applying them. But a decent entry-level wax and a few microfibre applicator pads and microfibre cloths for buffing can be had for less than £20
- Makes for easy cleaning - think of wax like the non-stick coating on your saucepans. Dirt, bugs, road tar, tree sap, etc all have difficulty adhering to wax and therefore you can wash them off much easier.
- Looks good - I'm aware that personal preferences vary but personally the glossy sheen you can get from even a modestly priced wax looks damn good IMO
- Easy to re-apply to very small sections of the car following e.g. a chip repair.
- Decent quality waxes will provide a modicum of UV protection to the paint
Disadvantages
- Doesn't last that long - ideally you're going to want to be re-applying your wax coat every 2-3 months. Less if you drive a lot of miles or in harsh conditions
- Doesn't protect against stone chips - very light scratches and swirl marks are something wax can cope with. Heavier impacts such as stone chips are beyond it.
- It's labour intensive - doing it properly involves a good hour or two of elbow grease if applying by hand, and you need favorable environmental conditions too - if it's too hot, that's bad - if it's too cold, that's bad - if it's raining, forget it.
"Nanotech" coatings
A lot of science-y words get thrown around to describe these - but essentially they are wax taken to the next level. More durable and protective than wax.
Advantages
- You can try this at home! If you are prepared to put the time and elbow grease in you can do this yourself, sites like Detailing World will provide you with more information then you ever wanted to know about different products, and ways of applying them.
- Makes for easy cleaning - think of it like the non-stick coating on your saucepans. Dirt, bugs, road tar, tree sap, etc all have difficulty adhering to the coating and therefore you can wash them off much easier.
- Relatively easy to re-apply to very small sections of the car following e.g. a chip repair.
- Better UV protection than wax
- Harder-wearing than wax - depending on the product and conditions you can go 12-24 months between re-applications
- Good protection against corrosive threats such as bird droppings and tree-sap
Disadvantages
- Limited protection against stone chips - very light impacts, scratches and swirl marks are something they can cope with. Heavier impacts are beyond it.
- It's more involved than simple waxing - these coatings only really work properly if they are applied to a truly defect and blemish-free paint surface. So we're talking cleaning, claying, paint-correction with a mechanical polisher, the works - and that applies even to brand new cars!
- It's labour and time intensive - doing it properly can take a couple of days (did a brand new BMW once - took myself and a fellow detailing enthusiast about 20 hours) and you need favorable environmental conditions too - if it's too hot, that's bad - if it's too cold, that's bad - if it's raining, forget it.
- Not as cheap as waxing - you can go through £40-100 worth of product in a full job, and that's not counting the necessary tools. If you want a professional detailler to do this budget around £1000.
