premature wear of rear tyres on a FF car can indicate a few things being possible:
1. Tyre pressure. are the outside treads of the tyres much more worn than the central treads? or the other way round.
2. hows the weight distribution in your car? this should not contribute to much but more info may help
3. camber/toe-in of rear wheels. If the wheel wheels have incorrect camber/toe-in, this can lead to uneven/premature wear. This would need a bigger garage to check but is more that possible to cause problems you're experiencing.
4. brake balance. cars are meant to be set up front-heave with brakes. if the rear brakes are coming on too heavy, they may lock the rear wheels. This is a safety issue as much as efficiency issues.