În cazul în care lipsește certificatul de înmatriculare, mașina este respinsă.

În cazul în care means in the event that / in case / if it happens that. It is a more formal and bureaucratic-sounding expression than dacă, which is the normal everyday word for if.

So:

• În cazul în care lipsește certificatul... = In the event that the certificate is missing...
• Dacă lipsește certificatul... = If the certificate is missing...

Both are possible, but în cazul în care sounds especially natural in official instructions, regulations, and administrative language.

Lipsește is from the verb a lipsi. In this sentence, it means is missing or is absent.

So:

• lipsește certificatul = the certificate is missing

A useful thing to notice is that Romanian often uses a lipsi in a structure that feels a little different from English. Instead of saying something like they did not provide the certificate, Romanian can simply say the certificate is missing.

Here, certificatul is the thing that is absent.

Certificatul is the certificate. The ending -ul is the definite article attached to the noun.

Romanian usually puts the definite article at the end of the noun:

• certificat = a certificate / certificate
• certificatul = the certificate

In this sentence, it refers to a specific required document, so the certificate is natural.

De înmatriculare means for registration / of registration.

So:

• certificatul de înmatriculare = the registration certificate

This is a very common Romanian pattern:

• document de identitate = identity document
• număr de telefon = telephone number
• certificat de naștere = birth certificate

The word înmatriculare means registration, especially for a vehicle.

The comma separates the conditional clause from the main clause.

Structure:

• În cazul în care lipsește certificatul de înmatriculare = subordinate clause
• mașina este respinsă = main clause

This is similar to English:

• If the registration certificate is missing, the car is rejected.

Romanian normally uses a comma after this kind of introductory clause.

Mașina means the car, while mașină means a car / car.

Again, Romanian adds the definite article to the end:

• mașină = car
• mașina = the car

In formal rules and procedures, Romanian often uses the definite form even when English might translate it more generally. So mașina este respinsă may mean literally the car is rejected, but in context it can function like the vehicle is rejected in a general rule.

Este respinsă means is rejected.

This is a passive construction:

• este = is
• respinsă = rejected

The form respinsă is feminine singular because it agrees with mașina, which is a feminine singular noun.

Compare:

• mașina este respinsă = the car is rejected
• autoturismul este respins = the vehicle is rejected

Here autoturismul is masculine, so the form is respins, not respinsă.

In this sentence, it is best understood as part of the passive meaning is rejected.

Romanian often forms the passive with:

• a fi
  • past participle

So:

• este respinsă = is rejected
• a fost respinsă = was rejected
• va fi respinsă = will be rejected

The participle behaves like an adjective in agreement, which is why it changes form:

• respins (masculine singular)
• respinsă (feminine singular)
• respinși (masculine plural)
• respinse (feminine plural)

Yes, depending on context, that may be the most natural English translation.

Literally, mașina este respinsă means the car is rejected. But in practical contexts such as a vehicle inspection, idiomatic English might say:

• the car fails
• the car is failed
• the vehicle is rejected

So the Romanian is passive and formal, while English may use a more natural industry-specific expression depending on the situation.

Romanian often prefers a structure built around a lipsi (to be missing / to be absent) in formal contexts.

So instead of:

• nu există certificatul
  or
• nu este certificatul

Romanian naturally says:

• lipsește certificatul

This is a standard, idiomatic way to say that a required item is not present.

Yes, but the original order is the most natural for a formal rule.

Original:

• În cazul în care lipsește certificatul de înmatriculare, mașina este respinsă.

You could also say:

• Mașina este respinsă în cazul în care lipsește certificatul de înmatriculare.

This is still correct, but it puts the result first and the condition second. The original version sounds more like official written instructions.

Yes, in normal modern Romanian, în cazul în care is typically followed by the indicative, not a special subjunctive form.

So:

• în cazul în care lipsește...
• în cazul în care apare...
• în cazul în care nu aveți...

This is similar to English if clauses that use an ordinary finite verb.

A more everyday version would be:

• Dacă lipsește certificatul de înmatriculare, mașina este respinsă.

Or even, depending on context:

• Dacă nu ai certificatul de înmatriculare, mașina e respinsă.

Differences:

• în cazul în care → more formal
• dacă → more neutral/common
• este → more formal/full form
• e → conversational short form of este

So the original sentence sounds like something from an official regulation or inspection checklist.