How to make wiper delay switch

I have a 1982 Datsun 210 2 door sedan with a 1.2L 4 cylinder engine. I would like to make a wiper delay switch for my wipers. I know I need a variable resistor and maybe a capacitor. So....

What impedance of resistor should I use, and same with a capacitor (if needed)? I have a bunch of variable resistors of all different varieties. And I have some capacitors. Also how do I hook up the wires from the wiper lever?

Unless this is something your wanting to make yourself, look at this:http://www.jcwhitney.com/autoparts/Product/tf-Browse/s-10101/Pr-p_Product.CATENTRY_ID:2004484/p-2004484/N-111+10201+600003811/c-10101/reviewflag-1#review

probably could find the same thing at most any parts place.

That's pretty cool! I didn't know that kind of thing existed. I was just going to try and install a variable resistor but this seems more practical.

Thanks!

the simplist way of building this circuit would be to use an adjustable timer relay. Thats about all you'd need. But honestly, you'll have a dang hard time building it cheaper than the above product, and it definitely wouldn't have the fit and finish of the above product