Assalamu Alaykum
I have experience in this that may be helpful to you. I have been previously had two Personal Contract Hire (PCH) cars. This works in the same way as a rental, as you only pay to hire the car for a set number of years and then return it. As such no loan or interest (APR) figure is involved.
With regards to PCP and Hire Purchases, these usually include financing with interest (with some exceptions from dealers such as Vauxhall). There is also this company InterestFree4Cars: Cars On Finance, 0% Car Finance Deals, 0% Minicabs | Interest Free 4 Cars
Insha Allah the muftis will get back to you around this to provide further guidance.
JzkAllahkher
Nawaaz