assalamulaikum I want to know if I go salat in a car which is paid with interest money is my salat valid. secondlly I once got benefits which i think i should'nt have because when i work a certain amount of hours i get tax credits (benefits) i used the tax credit money to pay for installing parking sensors in my car. But that week I called in sick from work, by lying I had a flu. In reality if my work knew I was lying I would have been dismissed. and if you are dismissed your tax credit stop. so i paid for parking sensors with money maybe wasnt suppose to have. but i think you continue to get tax credit for 4 week if you are dismissed but im not sure.. Is my salat valid if i drive to mosque in this car. please answer directy

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

Your prayer is valid in the sense that it suffices and clears your liability for that religious obligation. As for whether it is accepted or not and whether you will be rewarded for it or not, this is a matter of the Unseen that only Allaah knows. Even the pious do not know whether Allaah has accepted their prayers or not. The honorable Companion Fadhaalah ibn ‘Ubayd said, “If I knew that Allaah accepted even the weight of an atom (or a small ant) of my good deeds, this would be more delightful to me than the whole world and all its pleasures, since Allaah The Exalted says (what means): {Indeed, Allaah only accepts from the righteous [who fear Him].} [Quran 5:27]”

Ibn Al-Qayyim wrote, “‘Abdullaah ibn ‘Umar said: "If I knew that Allaah accepted one prostration from me, nothing would be more loved to me than death; {Indeed, Allaah only accepts from the righteous [who fear Him].}"”  [Ar-Rooh] 

The dear questioner should repent for the sin of engaging in an interest transaction and unlawfully consuming something that did not belong to him. The Prophet, sallallaahu ‘alayhi wa sallam, cursed those who consume usury, those who pay it, those who are witnesses to it, and those who record it. [Muslim] What good would the car do you if you were among those whom the Prophet, sallallaahu ‘alayhi wa sallam, cursed?

So, you must turn back to Allaah and repent from that sin, regret committing it and resolve never to do it again. You should also repent for taking this money (tax credits or benefits) by lying. If you did not deserve that money according to the conditions stipulated in the agreement between you and your company, then you have to give it back.

Allaah Knows best.