Dr. S. Radhakrishnan in his 'Indian Philosophy' (Vol I) lists some of the quotations attributed to Charvakas. I'm quoting few of them below.
The Agnihotra, the three Vedas, the ascetic's three staves, and smearing oneself with ashes —
Brihaspati says, these are but means of livelihood for those who have no manliness nor sense.
If a beast slain in the Jyothishtoma rite will itself go to heaven,
why then does not the sacrificer forthwith offer his own father?
If the Sraddha produces gratification to beings who are dead,
then why not give food down below to those who are standing on the house-top?
While life remains, let a man live happily,
let him feed on butter though he runs in debt;
When once the body becomes ashes,
how can it ever return again?
If he who departs from the body goes to another world,
how is it that he come not back again, restless for love of his kindred?
Hence it is only as a means of livelihood that Brahmans have established here
all these ceremonies for the dead, — there is no other fruit anywhere.
The three authors of the Vedas were buffoons, knaves, and demons.
All the well-known formulae of the pandits, jarphari, turphari, etc.
and all the obscene rites for the queen commanded in Aswamedha,
these were invented by buffoons, and so all the various kinds of presents to the priests,
while the eating of flesh was similarly commanded by night-prowling demons.
Radhakrishnan observes, "Obviously this account has an element of caricature of the cArvAka position. A philosophy professed seriously for centuries could not have been of the coarse kind that it is here reported to be."
However, I look at it differently. I have previously argued that Carvakas were fringe philosophers as they were always against the authority (which in religious matters were invariably Brahmins). In my opinion, the above quotations are nothing but frustration from their part. Common people understand only blunt and direct arguments. They were probably resorting to coarseness so that common people could see the commonsense in it.