LIGHT super-charging of a 2004 Jaguar XJ VanDen Plas

I would like to explore the possibility of LIGHTLY super-charging a Jaguar XJ--if such a thing is possible!--such that none of the other major components of the car (transmission, differential, etc.) would need to be strengthened &/or reinforced.
I vaguely recall (for example) coming across information that the Garrett (?) super-charger has been used to mildly (or SLIGHTLY) super-charge certain models of Bentleys.