  We define localized modulation maps and modulation spaces of symbols suited
to the study of Rieffel's deformation quantization pseudodifferential calculus.
They are used to generate Hilbert space representations for the quantized
$C^*$-algebras, starting from covariant representations of the corresponding
twisted $C^*$-dynamical system. In the case of an Abelian undeformed algebra,
orthogonal relations and extra information about the representations are
obtained.
