i suspect there are clearance issues, as the various alloy retailers do not show up sizes above 16 for uno wheels. they may be being conservative, but 19 is quite a bit above 16. if you really really want bigger wheels & budget isn't an issue, you could change the suspension and raise the car just for that purpose - but would still need to check the offset / inset clearances - i forget what way they are. also remember that bigger wheels = needs better braking for them (tho going from cast to alloy could-should make them lighter, it depends & i wouldn't know offhand.) and your speed indicator and so forth will change readouts, & there's other things affected too because of the rolling circumference changes.