The unfixed characters featured in Euro Prestige Plates (i.e. your combination excluding the fixed Q) are spaced in the middle of the plate area after the European crest. This means that shorter combinations show more spacing around the combination.
One space is allowed within your chosen combination on all formats except Euro Prestige 6 characters slimline. Euro Regular size is the only size plate that accommodates a space on the Euro Prestige with 6 characters. The space can be added within the unfixed characters where desired, but not before or after the combination, which is predetermined spacing.