Because it is so "crappy" and BMW also OEM Techron Cleaner with their branding.

STP, never worked a thing. Prestone I don't know. I am happy with it's effect, that's it. The other brand that works is Lambda.

I can't possibly be assuring you that it will help, cause I am not selling the product either. But just that as to me, it works on whatever car I tested, be it my 16 years old kembara, to 5 years old City/Civic/Merc. And IMHO, RM35 is not too much hurt to try?

And also IMHO, engine flushing wise... Use Lambda Primer Set will yield better result and more economical.

I had it manually cleaned. The workshop guys removed the intake manifold and soaked the valves in a solution for a couple of hours before scrubbing all the carbon out. BMW has their own procedure for their DI engines which is called walnut blasting. It seems to be a normal procedure for them to have their valves blasted once in a while.

For reference, take a look at how bad the carbon buildup was on my car

Yup it's pretty bad. But its common among the VW/Audi 2.0TFSI engines and on the BMW DI engines. Doing a full carbon cleaning once in a while is common practice for owners here. But, an italian tune up every now and then helps keep our valves clean

Here's one of the valves after cleaning:

Kembara - 150K mileage

C200 CGI - 46K Mileage

FD2R - 42K Mileage

Getz - 58K Mileage

Hummer H3 - 16K Mileage

Honda City - 98K Mileage