Indeed, this seemed to indicate that the rent has increased disproportionately. The article mentions that the rent would cost $500 in today's dollars. That's very cheap for 4 bedroom apartment everywhere in western world, especially in London.

Maybe that car was really rubbish by today's standards and technology-wise therefore it is expected that now the real costs have come down. But with apartments I don't think there is that much of an improvement that justify average increase from $500 to $5000.