Rally tyres are pretty high profile usually and they also have a very square shouldered profile that would be causing a lot of the problem.

A properly sized road tyre would go a long way to fixing your issues.

Also, as a side note, if those rally tyres have the statement "for competition use only" or "offroad" or "not for road use" on them, you wont have any insurance etc should you have a accident etc.. Just a warning..