Going to be getting under the car this weekend, getting a rattle around 2k revs that sounds like its coming from underneath, will be replacing the hangars and cat to manifold gasket kit, so whilst im there I will also be checking that the heatshields aren't rattling like I've read on here loads. If it does turn out to be a heatshield issue what washer sizes are people using on the bolts to solve this? Rubber ones do the job? Just so I have everything to hand, cheers in advance.