Relay Buzzing

Completed initial testing with reed relay.  Works as advertised, very quiet with nearly imperceptible buzzing during voltage rise/fall.  Mounted underdash it should work well for my application. 

Was talking with an electronics expert and he suggested I reconsider the transistor setup.  It will give nice feedback of the voltage rise/fall and be completely noise free, maybe with longer life.  The only concern would be heat.  Any idea how much heat a low voltage LED setup would generate through the transistor?  Maybe 150ma total current, no more than 200ma.  Would I need to heat sink the transistor or is it of little concern in my application?

This may have been posted before but I located an excellent solid state relay for auto applications, the Hongfa HFS33.  Silent, with easy screw terminals.  Rugged construction and no heat with my low voltage LED install.  Much better than the fragile reed relay (yes, I broke two reeds simply trying to wire and shrink wrap).  More expensive at $25 shipped but well worth it IMHO.

Manufacturer product page http://www.hongfa.com/pro/HFS33_en.html

Article discussing use http://autospeed.co.nz/cms/title_Using-Solid-State-Relays/A_110574/article.html

Web store http://www.futurlec.com/Relays/SSRDC100V40A.shtml [Note: This is only online retailer I could find.  Relay is shipped direct from Taiwan, took about 10 days.  No problem with Futurlec, order handled professionally.]