Learn Russian: Пусть машина ржавая, но мы всё же радуемся поездке. - Even if the car is rusty, we still enjoy the trip.

While пусть often means "let" (as in "let them go"), here it sets up a concessive clause. When paired with но (but) or всё же (still) in the second half of the sentence, it translates to "Even if..." or "Granted that...". It acknowledges a negative fact while emphasizing that the main action happens anyway.

Could I just use хотя (although) instead of пусть?

Yes, хотя машина ржавая works perfectly and means almost exactly the same thing. However, using пусть gives a slightly more conversational, dismissive flavor, like saying "Okay, granted, the car is rusty, but..."

Why is the word for "trip" in the dative case (поездке)?

It is because of the verb радуемся (we enjoy / are happy about). The verb радоваться always requires the object that causes the joy to be in the dative case, never the accusative. This is a common trap for English speakers who want to directly translate "enjoy the trip" using a direct object.

What is the role of всё же in the second clause, and is it mandatory?