[tacuba]

This is from the book I'm currently reading (translated from English to Spanish).

"Cuando Wense se acerca a la improvisada caseta de cobro, una destartalada camioneta pickup en la que el vidrio del ventana del lado del pasajero está roto, únicamente lo suficientemente para permitir que se lleve a cabo la transacción, regatea sin cesar pero en vano, con el vendedor."

My question has to do with the para permitir que part. I know that para que always triggers the subjunctive in adverbial clauses, but does that rule still apply when there is a verb (like permitir) in between the para and the que, and is that why llevar is in the present subjunctive?

Thanks in advance