BMW Repair: FRONT END, 2000 bmw 323ci, bmw 323ci

Question
hello,

im hoping that you can help point me in the right direction i own 2000 bmw 323ci first it seams that everyone mechanic i take it too (not specializing bmw dont really know what they are doing) but anyway im going to ask you about two of the issues im having.. when my car accelerates between 2000-2500 rpm theres a grinding sound/rumble coming from center console but goes away when you go faster and i believe the car runs perfect..1 mechanic said guidbo another said differential bearing the mechanic that said differential bearing said the guidbo isnt bad..have you  ever heard of this or is there anything else i should check for?? second prob  another when accelerating front tire sounds like a flapping noise very weird also at slow speeds but drives perfectly straight..i have three aurora tires and 1 futenza i believe ..last year i had control arms and bushings done.,... how do i tell if this is normal road noise or more serious problem any suggestions you might have will be greatly appreciated,,my car has 95,000 miles..

thank u very much

Answer
The noise that you hear while accelerating I would say is the center bearing on the drive shaft,as far as the front end noise it would matter when it occured.If it increases on turns or if it is constant.On turns it maybe a wheel bearing if it is constant it may be the tires if they are worn.