Taking old part home

I am having a new power steering rack put on my 2006 XC70 at the cost of $1000.00 only for the part ..I want to take MY used one home and they are charging me $100.00 to do so ..The want to revamp it and I guess sell it as a used part....But should it not be mine to do with as I please.Not too happy and rather confused...

[NativeJesus]

Usually, they charge this up front and reimburse you when they receive your used part. This is what is called the "core charge". In your case it was not on your initial bill as you had it installed at their place and they fixed the price with their core reimbursement, they bought it from their supplier and WILL NOT be reimbursed the core charge they paid if you bring the part back at your home.

So you are in your right to ask for it, but it would be honest to give them the money they paid up front to their supplier.