It does change it, since it lumps all the cars in a particular class together on the consoles, and then only gets a selective dataset of that class (first 20 times or whatever) In that case the database only fetches 20 times. So in order to apply a filter it would have to fetch the entire dataset of all times -however large it is- each time (to get rid of the McLaren F1 times for example) to be able to effectively filter out one single car.
On PC, it can do it just fine since there's no restrictions on the amount of leaderboards and it's per car. So it can happily fetch it at 15-20 records at a time. Something like that anyway.