I am planning to install a backup sensor for my ES330 ... I got a quoatation to get it installed $450.00 .. (Crimestopper sensor) I am not very sure how good is this brand and also the $ amount.. sounds like it's too expensive wherelse on ebay the parts alone does not costs more than $50.00 ... Any suggestions?? and usually how difficult is it to get something like this done by yourself??

All I need is a beeper to beep in a higher frequency when I am nearing any obstacle... I don't even need a display...

Thanks Guys...