Originally Posted by Strife

It can be done, even by an old fart (47) with eyesight not what it was. A temp-controlled iron with small tips, flux pens, good (but not expensive) tweezers, and $5.00 of cheap jewelers' loupes! Because it was getting impossible to hack without being able to to do surface mount, I designed and built a microprocessor controlled nixie-tube watch as my first try at it. In some ways, it's actually easier than through-hole (except when you get down to super-fine-pitch or ball-grid array chips, then the equipment gets astronomically expensive).

On the concern about RC constants in the cruise circuit, I'd find it hard to beleive that MB would design a circuit where 10% would be critical, particularly on a cap. These things aren't really even that close (for long!) in reality, and it is possible to design analog circuitry where the effects of conponent tolerance are minimal. Just the extreme temp variations in a car would cause problems in an overly-sensitive circuit. If there are actually any timing-critical caps, they are probably polystyrene or specially made disk caps. Using an electrolytic in a timing circuit is generally not a good idea (but IANAEE).

For example, I'll bet that many electrolytic caps in my (working, for now) cruise control module are probably +0/-40% or more right now, given their age.