Несмотря на то, что дворники работают быстро, на большой скорости стекло всё равно становится грязным.

Несмотря на то, что + clause is a fixed concessive conjunction meaning although / despite the fact that and it must be followed by a full clause (with a verb):

• Несмотря на то, что дворники работают быстро… = Although the wipers work fast…

Несмотря на + noun/pronoun is used when what follows is a noun phrase, not a clause:

• Несмотря на дождь… = Despite the rain…
• Несмотря на это… = Despite that…

Because что introduces a subordinate clause, and Russian normally separates the main clause and subordinate clause with a comma. In this set phrase, the comma is written as: несмотря на то, что … (it’s treated like a complex conjunction).

The sentence starts with a subordinate concessive clause:
Несмотря на то, что дворники работают быстро, …
When that subordinate clause comes first, it’s separated from the main clause by a comma.

In everyday Russian, дворники can mean: 1) janitors / yard keepers (building staff), and
2) windshield wipers (car part)

In this sentence, it clearly means windshield wipers, because it talks about стекло getting dirty while moving at high speed.

Работают (imperfective) describes an ongoing/repeated process: the wipers are functioning in general while you’re driving. Perfective would suggest a single completed action, which doesn’t fit well with the idea of continuous wiping.

На скорости is a common Russian pattern meaning at (a certain) speed / while moving at speed.
After на in this meaning, Russian uses the prepositional case:

• скорость → (на) скорости

So на большой скорости literally = at a high speed.

Both can be used, but they have slightly different “feel”:

• на большой скорости is very common and idiomatic for “at a high speed / when driving fast”
• на высокой скорости is also correct and may sound a bit more “technical” or neutral

In many contexts they’re interchangeable.

The main clause is: стекло всё равно становится грязным.
Here стекло is the grammatical subject: the glass/windshield becomes dirty.
The wipers (дворники) are only in the subordinate clause.

In modern Russian, становиться is the normal verb for to become. The -ся form is basically standard here; it doesn’t mean the windshield “makes itself” dirty in a literal reflexive way. It’s just how Russian forms this intransitive “change of state” verb.

After становиться (and many other “to become / to seem / to remain” type verbs), the complement is typically in the instrumental case:

• становиться + instrumental → становится грязным

This is the standard pattern for describing what something becomes.

Всё равно means anyway / all the same / still and emphasizes that the result happens despite the wipers working fast.
It’s flexible in position, for example:

• стекло всё равно становится грязным (very natural)
• стекло становится всё равно грязным (possible but less natural)
• всё равно стекло становится грязным (also possible, more emphasis up front)

It’s not fixed. Russian word order is flexible and used for emphasis. For example:

• Несмотря на то, что дворники работают быстро, стекло всё равно становится грязным на большой скорости. (moves the speed phrase later)
• На большой скорости стекло всё равно становится грязным, несмотря на то, что дворники работают быстро. (puts the “high speed” condition first)

The original order is very natural: concession first, then the key condition (на большой скорости), then the outcome.