The suspects - a 56-year-old from Bilston and a 76-year-old from Kingstanding in Birmingham - were arrested on Thursday night in connection with Jomaa Jerrare's death.
Ms Jerrare, aged 52 and from Heath Town in Wolverhampton, was found dead in a layby on Bridgnorth Road in Perton in the early hours of August 9.
Her body had been set on fire next to the main road between Wolverhampton and Bridgnorth.
Staffordshire Police confirmed on Monday morning they had been granted extra time by magistrates to question the suspects.
A spokesman for the force said: "Detectives are continuing to question two men arrested in connection with the death of Jomaa Jerrare after they were granted an extension by magistrates. We will provide further updates."
The longest total extension magistrates can grant is 96 hours, after which the suspects must be released or charged.
Staffordshire Police had already been granted extra time to interrogate the men, with suspects ordinarily only allowed to be held for 24 hours without charge.
A man who was previously arrested on suspicion of murder after being seen near where Ms Jerrare was found was released and will face no further action after accounting for his movements.
It took police two days to identify Ms Jerrare, with officers initially believing the body belonged to a younger woman. The severity of the burns to her body meant it was difficult to establish her age, gender and ethnicity.
Ms Jerrare had not been seen by her family for six weeks or by neighbours for four weeks.
But Detective Superintendent Tom Chisholm, who is leading the investigation for Staffordshire Police, said it was not unusual for her to be out of contact for a length of time. She had not been reported missing.
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Det Supt Chisholm said she had “lots of friends and acquaintances” and teams were trying to establish if she had any “long-term partners”.
Ms Jerrare lived alone in a flat in a high-rise building in Heath Town and had lived in and around Wolverhampton for most of her life.
Police believe that she was killed before being driven to the layby but it is not yet known where she died.
Further tests were also due to take place to establish the cause of death after a post mortem proved inconclusive.