Mindboggling Magritte, artists respond to a world in peril and a squished Citroën – the week in art

<p>The French surrealist still confounds, artists look at the past, present and future of the planet and Rachel Kneebone’s crazed delights blend into the Wallace Collection – <a href="https://www.theguardian.com/artanddesign/2015/oct/19/sign-up-to-the-art-weekly-email">all in your weekly