  We prove the Baum--Connes conjecture with arbitrary coefficients for some
classes of groups:
  (1) Linear algebraic groups over a non-archimedean local field.
  (2) Linear algebraic groups over the adeles of a global field k, provided
that at every archimedean place of k the associated Lie group is amenable.
  (3) All closed subgroups of the above groups. This includes linear algebraic
groups over global fields - with the same condition as in (2).
  Update: proof of main results incomplete, maybe not repairable.
