I fitted stick on parking sensors on my landy for when the missus is driving. Took me all of 10 mins and the kit cost about £10 on ebay. If the sensors get covered in mud they do beep all the time when reversing until you wipe em.
this one looks like it has stick on sensors...
Backscan Car Reversing Parking Sensor - Brand New on eBay (end time 22-Jul-10 19:54:48 BST)
Oh, the old 'for when the missus is driving'? Bollox yer puff!
Ratty cun't paaaark, Ratty cun't paaaark, ner, ner, nah, ner, ner!
I can't be the only one who thinks if you can't reverse and park using your eyes, mirrors and knowing the dimensions of the vehicle you're driving, you shouldn't be on the bloody road. Surely.