I got one put on there two weeks ago, and thought they'd done a very good job. Then a couple of days later I found that they had needed to move part of the fuel system to attach the towbar, and had reattached the part with cable ties
My last towbar came courtesy of TradeMe... Was for a mid 90's Lancer that I bought for a hack - found one within two weeks of looking - 20 bucks plus 15 for shipping ex Auckland. Came with trailer socket, and was a breeze to fit - even came with the fitting bolts. Just get under the car, get someone else to hold the whole shebang in place, bolt 'er up, torque the bolts, and do the wiring (assuming you are capable - otherwise an auto elec could hook you up pretty quick).