Paul
I have just read that halfords Guarantees demon foam a streak free, spotless finish Wow that is a serious claim and trading standards may have something to say after your experience .

We have serious hard water issues round here and if you use tap water you get lime which is corrosive (bird being the most caustic substance known to cars). If you wash cars in sunlight or warm, you will get droplet marks and if you read the small print I bet a good steak dinner it will have some get out clause. For tens of years, we have washed cars without snow foam and other fancy guff, I use a bucket, car shampoo and water through power washer from rain water butt and get clean car, no scratches no marks and no fuss or expensive products. It all hyped up by product companies as must haves. Rant over.  2x TDV6. SE and HSE. Both returned to sender with issues👀
TDV8 Sport HSE...... Gone. Loved it but it didn't love me!!
Now rolling in MY10 Fullfat TDV8 Vogue. Slammed it to go round corners🙈
Cruising daily #56 mph in a Volvo V8. 😱
Lots of other toys in the cupboard...😜

Couldn't agree more.
My cars have always been treated to a bog standard wash and I've never suffered any paint issues.
A couple of guys I work with give their cars the full treatment and to be honest visually there is no difference between my ecomony wash and their product laden multi hour wash, waste of time and money in my opinion.

Nik. 2015 Golf R DSG
Gone 2013 Mercedes C220 CDi AMG Sport Plus
Gone 2008 2.7 RRS HSE

Yea I bought it too as I wanted to save on buying the lance after shelling out £45 on a wax, I thought £15 on the foam would be a nice touch. It worked nicely foaming and I was happy watching it. Says it does 15 washes, but to cover the RRS it took around 1/4 off the bottle. So guessing its more close to 4 washes

I read to agitate it with a cloth, so I done this too, it smelt lovely btw, my girls wanted to lick the car lol. Once I done this, I expected it to all just run off the car, I then resorted after 5 mins to rinse it, glad I did.

It left a lot of marks that I had to microfibre towel off, but it worked okay. Interesting others have had the same issues, my car is grey, so on a black it would be worse.

I clayed it after and also ran by hand some swirl corrector to help before polishing it. But it all worked out in the end, what did we ever do before microfibre towels? I love them!

The new wax made even a metallic grey look amazing, I regret not getting black, but the grey is really starting to grow on me. I might even like it more once I finish with the mods. 

SNOW IN ACTION
more on the floor than the car was told as the car had been waxed before the foam wouldn't stick just ran off

A picture of mine before it was paint corrected and waxed. Autoshine snowfoam used on mine though.

Why is using this foam better then using a bottle of tfr?

TRF will discolour/fade any susceptible plastics and paint finishes. I'd shy away from TFR to be honest.
If you want something safe with similar cleaning abilities, check out Bilt Hamber's Surfex HD  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

I think TFR and snow foam is the same except one foams more. What is the use of snow foam if it does not remove traffic film and if it does then it is a TFR. There are TFR that are not caustic. The local hand car wash will use very aggressive TFR because
It cleans and is quick the problem being is it continues to work if not washed off very throughly. Plastic trim will suffer badly.

Some snow foams just loosen dirt and still require the car to have a full mitt/sponge wash. You can foam with just a shampoo Some people will use snow foam just to remove the heavy crud, then jet

At the end of the day, it's your own motor so you use what you see fit , but for me personally, I'd not use a TFR be it caustic or non-caustic  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

What I am trying to say is that snow foam is TFR but with a foaming agent added at least that is what my chemical suppliers tell me. I just don't want people to be hoodwinked into thinking snow foam is like a shampoo. However I am not a chemist and just take my suppliers word for it and if I have had the wool pulled over my eyes I would like to be told
Terry

I think in some circumstances you are right , but in others snow foam is just a shampoo with a foaming agent.
...the market has become saturated with snow foams over the last few years <excuse> and there are a lot out there that are next to useless in my opinion.

As I say, I use Bilt Hambers Surfex HD, it'll safely remove the grime and in some cases will result in a touch-less wash (after a snow foam and jet spray) that leaves the body and wheels 95% clean  ON THE WAY: BMW F21 M140i
MERCEDES GL350 - Metallic Navy Blue w/Grey interior

GOING: BMW F31 335D MSport+ xDrive Touring
GONE: Land Rover Discovery 4 HSE - Stornaway Grey w/Black Interior (wish we'd kept it )
GONE: BMW F10 520D MSport - Carbon Black
GONE:MY12 RRS SDV6 HSE Sumatra/Ivory/Grand Black Privacy glass

I've never had an issue with tfr on my motorbikes, cars or caravans and my mate used it for his valeting business too.

I do like the look of snow foam though from a childish point of view

I use Bilt Hamber HD in my foam lance. Brilliant. However don't let it dry out.
Then dry with Autoglim Aqua Wax.
I find it very good.